The tables currently have 9450 entries from 92 different contributors


last updated at 2026-02-27 12:59:46

Top Contributors

LJCR 2736
A. West 2388
Franco Atzeni 1073
Jan de Heer and Steve Muir 846
Colin Barker 312
Terenzio Lazzarotto 225
Bluskov and Sidorenko 189
Dietmar Pree 188
Alessandro Jurcovich 187
Michael Dambmann 161
Marco Meoli 99
Moshe Milshtein 98
Anastasios Tampakis 91
Giovanni Acerbi 81
David A Balfour 64
Kamal Fadlaoui 61
Bluskov, Milshtein and Sidorenko 56
Flavio Perona 49
Sveta Marjanovic 43
Jan de Heer 42
Kleszek 37
Mathias Liesener 36
Rade Belic 27
Bluskov-sidorenko 26
Barnabas Toth 24
Andrei Ochmat 23
Kinski and Genivaldo Pereira 21
Weber Azevedo 20
Chaoying Dai, Ben Li and Michel Toulouse 19
Luciano Rezende 18
Felix Rodriguez Martin 16
Evandro De Simone 16
Adolf Muehl 14
Rade Belic and Jan de Heer 12
Vinicius Alves 12
Jiang Yong Ming and Jiang Kun Xi 10
Rosario Marino 10
Aline Marie Menezes Wanderlei 9
Jurek 7
Karsten Schlzel 6
777ch 6
W.h.mills and R.c.mullin 5
Stefano de Martino 5
Enzo Franzese 5
W.h.mills 4
Jan de Heer and Rade Belic 4
Roy Gourgi 4
Alessandro Jurcovich E Marco Meoli 4
Jiang Yong Ming 4
Sveta Marjanovic and Anastasios Tampakis 4
Antonio Franzese and Enzo Franzese 3
Iliya Bluskov 2
Claus Friis 2
Bluskov and Hamalainen 2
Guenther Schlegl 2
Sveta Marjanovicandanastasios Tampakis 2
Mario Pina 2
Alessandro Brozzetti 2
Tommaso Tanto 2
Marco Meoli and Franco Atzeni 2
Namyk Kemal Erdogan 1
W. H. Mills 1
Karsten Scholzel 1
Adolf Muehl and Dietmar Pree 1
Igor Lazebnik 1
Tung Le 1
Riccardo Bertolo and Francesco Santisi 1
A. Tampakis and A. Jurchovich 1
Kinsky and Genivaldo Pereira 1
Marco Meoli E Alessandro Jurcovich 1
Jose Milan Vega 1
Dietmar Pree and Adolf Muehl 1
Rade Belic and Dietmar Pree 1
A. Betten, R. Laue and A. Wassermann 1
Dietmar Pree and Rade Belic 1
Alexandre Spaeth 1
Chaoying Dai, Ben Li and Michel Toulouse, Reduced By Rade Belic 1
Daryl Burns 1
Steve Muir 1
Bigmax 1
Carmine Iorio 1
Alessandro Jurcovich E Claudio Tosi 1
Fair_play 1
Anastasios Tampakis and Sveta Marjanovic 1
Bluskov-greig-heinrich 1
Dbr58 1
A. Jurcovich E G. Acerbi 1
K 1
Bertolo-santisi 1
David Cushing 1
Michael Kiermaier, Vedran Krčadinac, Alfred Wassermann 1
Ralph Stömmer 1





Overall there have been 106353 entries from 214 different contributors

All-time Contributors






LJCR 58381
A. West 8115
Jan de Heer and Steve Muir 6136
Dietmar Pree 3669
Terenzio Lazzarotto 3389
Enzo Franzese 3000
Michael Dambmann 2254
Tommaso Tanto 1806
JCD Article 1632
Flavio Perona 1539
Rade Belic 1442
Franco Atzeni 1356
Marco Meoli 1316
Alessandro Jurcovich 1148
Kleszek 762
M. Wang 746
Jiang Yong Ming and Jiang Kun Xi 666
Rade Belic and Dragan Stojiljkovic 539
Sveta Marjanovic 515
Stefano de Martino 484
Colin Barker 457
Evandro De Simone 384
Antonio Franzese and Enzo Franzese 371
Anastasios Tampakis 352
Giovanni Acerbi 350
Gerald Unger 343
E. Franzese, A. Jurcovich E M. Meoli 326
Moshe Milshtein 320
777ch 288
Kinski and Genivaldo Pereira 278
Aline Marie Menezes Wanderlei 278
Bluskov and Sidorenko 245
Felix Rodriguez Martin 244
Barnabas Toth 228
Fair_play 225
Jurek 218
Pio Leonardi 194
David A Balfour 149
Steve Muir 131
Weber Azevedo 131
Jan de Heer 129
Francisco Carlos 127
Luciano Rezende 104
Vinicius Alves 95
A. Jurcovich, M. Meoli E E. Franzese 91
Kamal Fadlaoui 89
Jiang Yong Ming 85
Bluskov-sidorenko 82
Bluskov, Milshtein and Sidorenko 60
Alessandro Jurcovich E Marco Meoli 57
Nino Aspesi 54
Mathias Liesener 51
Dietmar Pree and Rade Belic 41
Jose Milan Vega 40
Chaoying Dai, Ben Li and Michel Toulouse 39
Jaera 38
Rade Belic and Jan de Heer 38
Enzo Franzese E Alessandro Jurcovich 37
Andrei Ochmat 31
Gino Grazin and Rade Belic 31
Marco Meoli E Alessandro Jurcovich 29
Alessandro Jurcovich E Enzo Franzese 28
Marco Meoli-alessandro Jurcovich-enzo Franzese 28
Dragan Stojiljkovic 27
Enzo Franzese E Marco Meoli 26
Antonio Franzese 20
Jan de Heer and Rade Belic 19
Adolf Muehl 17
Sveta Marjanovic and Anastasios Tampakis 17
A. Jurcovich, E. Franzese E M. Meoli 17
Roy Gourgi 14
Weberazevedo 13
Jinyuan Wang 13
Rosario Marino 13
Tarullig 12
Flavio.perona 11
Kabila 11
Igor Lazebnik 10
Alternatywa 10
Iliya Bluskov 9
Sildemar Castro 8
Marco Meoli and Alessandro Jurcovich 8
Marco Meoli-alessandro Jurcovich 8
Claudio Tosi 8
Riccardo Bertolo 7
Daryl Burns 7
Enzo Franzese E Dietmar Pree 7
Mario Pina 6
Karsten Schlzel 6
Hillary 6
Bluskov, Sidorenko 6
W.h.mills and R.c.mullin 5
Enzo Franzese E Weber Azevedo 5
Anastasios Tampakis and Sveta Marjanovic 5
Riccardo Bertolo and Francesco Santisi 4
Ivan Baptiste and Rade Belic 4
Rade Belic and Dietmar Pree 4
Leopio 4
W.h.mills 4
Sveta Marjanovicandanastasios Tampakis 4
Enzo Franzese E Nino Aspesi 4
Fctv 4
K 4
Alessandro Brozzetti 4
Claus Friis 3
Michael Damb 3
Marco Meoli Alessandro Jurcovich 3
Alessandro Jurcovich E Stefano de Martino 3
Marco Meoli E Enzo Franzese 3
Enzo Franzese E Michael Dambmann 3
Giovanni Acerbi and Terenzio Lazzarotto 3
Marco Marco 3
Alessandro Jurcovich E Free 3
Ok 3
Riccardo Bertolo and Jan de Heer 2
Genivaldo Pereira 2
Ricardo Ramalho 2
Paolo Ferlaino 2
Bluskov and Hamalainen 2
Adolf Muehl and Dietmar Pree 2
Karsten Scholzel 2
Meoli Marco 2
Tarullig / Aspesi 2
Alessandro Jurcovich - Nino Aspesi 2
Marco Meoli E Dietmar Pree 2
Weber Azevedo E Enzo Franzese 2
Enzo Franzese E Terenzio Lazzarotto 2
Enzo Franzese E Prize 2
Alessandro Jurcovich-marco Meoli-enzo Franzese 2
Spada Mauro 2
Alessandro Jurcovich E Claudio Tosi 2
Alessandro Jurcovich E Giovanni Acerbi 2
Covboy 2
Bertolo-santisi 2
Marco Meoli and Franco Atzeni 2
A. Betten, R. Laue and A. Wassermann 1
Namyk Kemal Erdogan 1
Alexandre Spaeth 1
Fernando Villanova 1
Steve Muir, Improving One By Jan de Heer 1
Chaoying Dai, Ben Li and Michel Toulouse, Reduced By Rade Belic 1
Jose Maria Milan 1
Grzesiek 1
Jan de Heer With Ininuga By Uros Boltin 1
Peter Rosendahl 1
Daniel Morais 1
Adolf Muehl and Rade Belic And Dietmar Pree 1
Lazzarotto Terenzio 1
Kinsky and Genivaldo Pereira 1
Gerasorte Online 1
W. H. Mills 1
Leo Pio 1
Qlatino 1
Simple Construction: Doubled (50,6,2) and Deleted An Element 1
Simple Construction: Doubled (50,8,2) and Deleted An Element 1
Simple Construction: Doubled (50,10,2) and Deleted An Element 1
Simple Construction: Doubled (50,11,2) and Deleted An Element 1
Simple Construction: Doubled (50,8,3) and Deleted An Element 1
Simple Construction: Doubled (50,9,3) and Deleted An Element 1
Simple Construction: Doubled (50,10,3) and Deleted An Element 1
Simple Construction: Doubled (50,11,3) and Deleted An Element 1
Simple Construction: Doubled (50,10,4) and Deleted An Element 1
42066 1
Quadrupling Construction 1
Altopalato Bellariva 1
Aspesi - Paramini - Tosi 1
Aspesi - Paramini - Marjanovic 1
Nino Aspesi - Moreno Paramini 1
Paramini and Kabila and Aspesi 1
Tung Le 1
Marjanovic Jurcovich Aspesi 1
Marco Meoli Sveta Marjanovic 1
A. Tampakis and A. Jurchovich 1
Nino Aspesi - Alessandro Jurcovich 1
Edi8 1
Tarullig/aspesi 1
Mario Tessuto 1
Alessandro Jurcovich-sveta Marjanovic-marco Meoli 1
J 1
Nino Aspesi E Enzo Franzese 1
Spada Mauro Bellariva 1
Marco Meoli - Alessandro Jurcovich - Enzo Franzese 1
A. Jurcovich, M. Meoli E E. Franzese E M. Meoli 1
Ricardo Sepulveda and Anastasios Tampakis 1
Bigmax 1
Kl 1
M. Meoli, A. Jurcovich E E. Franzese 1
Alessandro Jurcovich Marco Meoli Enzo Franzese 1
Enzo Franzese E Flavio Perona 1
Carmine Iorio 1
Dolce Remi 1
Bellariva 1
Tarullig and Kabila 1
Kair_play 1
Play_fair 1
A. Jurcovich, G. Acerbi E M. Meoli 1
Giovanni Acerbi and Alessandro Jurcovich 1
Aline Marie Menezes Wanderlei and Evandro De Simone 1
Don Backi 1
Paramini Moreno 1
Arrastre 1
Weber Azevedoandaline Marie 1
Socmel 1° 1
Altetnatywa 1
Spada Mauro 2202 1
Bluskov-greig-heinrich 1
Dbr58 1
A. Jurcovich, M. Meoli E G. Acerbi 1
A. Jurcovich E G. Acerbi 1
Giovanni Acerbi and Evandro de Simone 1
David Cushing 1
Franco Atzeni and Giovanni Acerbi 1
Michael Kiermaier, Vedran Krčadinac, Alfred Wassermann 1
Ralph Stömmer 1

Methods used in current tables

Local search 3557
unknown923
Simple construction 771
Private tools 716
Multiple 537
Dynamic programming construction 504
Lex covering 258
Constructed 226
Dynamic programming covering 131
Union optimization 122
Simple construction: combined 110
Wheeling systems checker 5 106
Simulated annealing 102
Tabu search started 96
Product construction 93
Wheel generator v2 90
Using wsc_5 78
Simple construction: multiple 70
Simple construction: induced 61
Wheel generator 57
Lexicographic greedy covering 57
Dynamic construction 49
Local search - bluskov pdo technique 34
Multi-stage optimization 33
Private tool 32
Simple construction: deleted element 31
Random greedy covering 23
Tabu search 22
Cyclic covering found by search program 21
Dynamic programming 21
Using wsc5 21
Cyclic covering 18
Simple construction: added element to c(v-1,k-1,t) covering 17
Steiner quadruple system 16
Jymccdd programming 14
Constructed using simulated annealing 11
Sidorenko construction 11
Wheeling systems checker 4 11
Cyclic construction 10
Design is based on c (v - 1, k, t) = b - v 10
Wsc4 10
Cyclic covering found by a search program 9
See paper by jrj abel et al. in discrete mathematics 307 (2007) 9
Simulated annealing covering 9
Simple combine 9
Group orbit covering design 9
Shortened covering 9
Nurmela and ostergard simulated annealing cover 8
Affine geometry covering 7
Wsc5 7
Component construction 7
Induced 6
Exhaustive search 6
Covering provided by rade belic 6
Extended covering 6
Steiner triple system 5
See jct series a 49, 308-322 (1988) 5
Nurmela-ostergard symmetric covering 5
Simple optimization 5
Sidorenko method 5
Wsc_5 5
Refinements 5
Wheel generator 1.7 free and wheeling systems checker 5
See journal 4
Constructed using difference families 4
Simple construction: added element to c(v,k-1,t) covering 4
Cyclic symmetry 4
Hanani construction (see canadian journal 4
Extraction/remainder 4
Nurmela-ostergard simulated annealing covering design 4
Wsc 4 + wg 2.3 4
Chain rule 4
Different methods (mainly simulated annealing) 4
Colex greedy covering 3
Mills, jcta 13 (1972) pp. 55-78. 3
Found by a hill-climbing program 3
Steiner system 3
Covering found by a hill-climbing program 3
Cyclic steiner system 3
Projective plane 3
Mills, ars combinatoria, 8 (1979) pg. 247 3
Mills, ars combinatoria, 8 (1979) pg. 231 3
Mills, ars combinatoria 8 (1979) pp. 199-315 3
Reverse engineering smaller systems 3
Using ininuga, by uros boltin 3
Covering provided by alex sidorenko (personal communication) 3
Wsc v4 3
Lottocp systems generator 3
Covering pairs by quads: mills, jcta 15:138-166, 1973. 2
Constructed using difference sets 2
Constructed by simulated annealing 2
Constructed using dynamic programming 2
Communicated by d. todorov, using pg(2,3) 2
Communicated by d. todorov, using pg(2,4) 2
Affine plane 2
Steiner system (derived) 2
Covering provided by john cock (personal communication) 2
Jcd 1998, pp. 21-41 2
Nurmela-ostergard simulated annealing covering 2
Hill-climb on affine orbits 2
Hill-climb on cyclic orbits 2
Simple method construction 2
Wheeling systems checker 2
Wsc 5 2
Improvement 2
From 1-flat on 42 numbers 1
Mill, jcta 15 (1973) 138-166 1
See paper in journal 1
Cyclic 1
Td(4,12) & 4 * c(15,4,2) 1
Td(4,15) and 4 * modified c(18,4,2) 1
Using rc(45,3,2) 1
Using a (v,4,22*)-pbd and c(22,4,2) 1
Td(4,18) + 4 * c(21,4,2) 1
Td(4,19) & 4 * c(21,4,2) 1
Using rc(54,3,2) 1
Using rc(60,3,2) by lamken and mills (1993) 1
Td(4,23) + 4 * c(25,4,2) 1
Td(4,24) + 4 * c(26,4,2) 1
Td(4,24) + 4*c(27,4,2) 1
Covering pairs by quints, mills & mullin, jcta 49:308-322, 1988 1
Covering pairs by quints, mullin, jcmcc 2:133-146, 1987 1
Cyclic covering on z5*z7 1
Cyclic covering on z3*z17 with one point at infinity 1
Using a 4−gdd 1
Using resolvable c(68,4,2), see lamken, mullen and rees (jcd, 1997-1) 1
Using resolvable c(72,4,2), see lamken, mullen and rees (jcd, 1997-1) 1
Covering found by john rawson 1
Produced with covermaster (by john rawson), wheelgenerator (by anastasios tampakis) and private tools. 1
See j comb des , vol. 15, no. 6, pp. 511-533, 2007 1
Using td(6,15) and 6*modified c(18,6,2,2) 1
Using td(6,16) and 6*modified c(18,6,2,2) 1
Communicated by d. todorov 1
Using a resolvable c(54,6,2,2) 1
From td(7,12) and 7*c(13,7,2,2,5) with 2 holes 1
From td(7,12) and 7*c(15,7,2,2,6) with 3 holes 1
Td(7,13) and 7 * modified c(15,7,2) 1
Mills, ars combinatoria, 8 (1979) pg. 254 1
Mills, ars combinatoria, 8 (1979) pg. 270 1
Doubling resolvable c(25,5,2) 1
Tripling a resolvable c(25,5,2) 1
Steiner system, taken 1
Doubling c(18,4,3) 1
Reverse engineering 1
Simple construction: 1
Doubling c(30,4,3) 1
See w h mills in congressus numerantium 10 (1974) pp563-581 1
Doubling c(36,4,3) 1
Doubling c(42,4,3) 1
Covering produced by floyd l. oats, using a ranking and reduction process 1
Wheel generator, based on jan de heer and steve muir work 1
Group theory 1
Covering 1
Quadrupling construction 1
Covering provided by konstantin katskov, found by exhaustive search 1
Private tools - assisted by wheel generator 1
Cyclic symmetrical 1
Combinado 1
Ex 8 1
Covering found by rade belic 1
Marco meoli 1
Superfluous-element hill climb on a covering 1
Ininuga (by uros boltin) 1
Ex 16 1
Ex 13 1
Ex 15 1
See designs, codes and cryptography 17 (1999), 181-186 1
Covering provided by dietmar pree 1
Method 1
Based on work by chaoying dai, ben li and michel toulouse 1
Block-array construction (gordon, patashnik, petro and taylor) 1
Ex 28 1
Superfluous-element hill climb on a random greedy covering 1
Block covering 1
Ex 54 1
Chain rule (64,32,6)x(32,24,6) 1
Several methods (including sa) 1
Normal methods 1
Quadrupling a full c(10,5,5) 1
Unusual methods 1
Construction combined 1
Wheel generator, based on chaoying dai, ben li and michel toulouse work 1
Based on work by kleszek 1
Wheel generator and covermaster 1
Korelacje_777ch__fairplay_v4 1
Simple construction: doubled (50,8,2) and deleted an element 1
Simple construction: doubled (50,10,2) and deleted an element 1
Simple construction: doubled (50,8,3) and deleted an element 1
Wheel generator and private tools 1
Wheeling systems checker, wheel generator and ininuga 1
Private tools, covermaster and wheelgenerator 1
Personale 1
From the article infinite classes 1
Wheeling systems checkers 5 1
Product type construction, based on nine (10,4,3) coverings whose union is a (10,4,4) covering 1
4 mols 1
Intelligent design 1
Product construction, improving on a jurcovich and meoli covering 1
Product construction, improving on a pree covering 1
Optimization 1
Personal 1
Sum 1
Extend steiner 2-designs by prescribing automorphisms and reducing the problem to an exact cover problem 1
Using wsc5 ex.941 ljcr 1
Star design; on coverings pairs by quintuples: the cases v=3 or 11 modulo 20 1
Using 5-gdd 1
A.m. assaf, w.h. mills, r.c. mullinon tricovers 1
A refinement 1
Combined (48,6,5) cover with (48,5,4) cover 1