The tables currently have 9137 entries from 85 different contributors


last updated at 2021-10-26 14:53:52

Top Contributors

LJCR 2969
Jan de Heer and Steve Muir 2383
A. West 902
Dietmar Pree 638
Colin Barker 317
Terenzio Lazzarotto 215
Marco Meoli 209
Stefano de Martino 183
Michael Dambmann 176
Alessandro Jurcovich 162
Anastasios Tampakis 99
Kleszek 80
Kamal Fadlaoui 73
Flavio Perona 60
Evandro De Simone 55
Enzo Franzese 48
Jan de Heer 43
777ch 35
Mathias Liesener 34
Sveta Marjanovic 32
Fair_play 30
Rade Belic 29
Jiang Yong Ming and Jiang Kun Xi 27
Barnabas Toth 25
Kinski and Genivaldo Pereira 25
Andrei Ochmat 23
Chaoying Dai, Ben Li and Michel Toulouse 21
Giovanni Acerbi 20
M. Wang 19
Felix Rodriguez Martin 18
Luciano Rezende 18
Aline Marie Menezes Wanderlei 18
Jiang Yong Ming 17
Adolf Muehl 14
Rade Belic and Jan de Heer 12
Vinicius Alves 12
Alessandro Jurcovich E Marco Meoli 7
Karsten Schlzel 6
Weber Azevedo 6
Alternatywa 6
W.h.mills and R.c.mullin 5
Roy Gourgi 5
W.h.mills 4
Jan de Heer and Rade Belic 4
Marco Meoli E Alessandro Jurcovich 3
E. Franzese, A. Jurcovich E M. Meoli 3
Iliya Bluskov 2
Claus Friis 2
Bluskov and Hamalainen 2
Guenther Schlegl 2
Sveta Marjanovicandanastasios Tampakis 2
Daryl Burns 2
Mario Pina 2
Covboy 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
Jaera 1
Kinsky and Genivaldo Pereira 1
Jose Milan Vega 1
Dietmar Pree and Adolf Muehl 1
Rade Belic and Dragan Stojiljkovic 1
Rade Belic and Dietmar Pree 1
A. Betten, R. Laue and A. Wassermann 1
Riccardo Bertolo and Jan de Heer 1
Dietmar Pree and Rade Belic 1
Alexandre Spaeth 1
Chaoying Dai, Ben Li and Michel Toulouse, Reduced By Rade Belic 1
Steve Muir 1
Marco Meoli-alessandro Jurcovich-enzo Franzese 1
Bigmax 1
Carmine Iorio 1
Marco Meoli-alessandro Jurcovich 1
Alessandro Jurcovich E Claudio Tosi 1
Tarullig 1
Giovanni Acerbi and Alessandro Jurcovich 1
Anastasios Tampakis and Sveta Marjanovic 1
Marco Marco 1
Claudio Tosi 1
Alessandro Brozzetti 1





Overall there have been 83646 entries from 190 different contributors

All-time Contributors






LJCR 51953
Jan de Heer and Steve Muir 6136
Enzo Franzese 2794
Michael Dambmann 2254
Terenzio Lazzarotto 1980
Tommaso Tanto 1799
A. West 1763
JCD Article 1632
Flavio Perona 1533
Dietmar Pree 1498
Rade Belic 1441
Marco Meoli 733
Alessandro Jurcovich 558
Jiang Yong Ming and Jiang Kun Xi 552
Rade Belic and Dragan Stojiljkovic 539
Kleszek 529
Colin Barker 457
Stefano de Martino 388
Gerald Unger 343
Anastasios Tampakis 340
E. Franzese, A. Jurcovich E M. Meoli 326
Kinski and Genivaldo Pereira 278
Aline Marie Menezes Wanderlei 263
Sveta Marjanovic 259
Felix Rodriguez Martin 244
Barnabas Toth 228
Fair_play 225
Evandro De Simone 217
Pio Leonardi 194
777ch 154
Steve Muir 131
Jan de Heer 129
Francisco Carlos 127
Luciano Rezende 100
Vinicius Alves 95
Giovanni Acerbi 94
A. Jurcovich, M. Meoli E E. Franzese 91
Kamal Fadlaoui 89
Jiang Yong Ming 85
M. Wang 69
Alessandro Jurcovich E Marco Meoli 55
Nino Aspesi 54
Mathias Liesener 47
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
Weber Azevedo 34
Enzo Franzese E Alessandro Jurcovich 34
Andrei Ochmat 31
Gino Grazin and Rade Belic 31
Marco Meoli E Alessandro Jurcovich 29
Marco Meoli-alessandro Jurcovich-enzo Franzese 28
Dragan Stojiljkovic 27
Alessandro Jurcovich E Enzo Franzese 26
Enzo Franzese E Marco Meoli 24
Antonio Franzese 20
Jan de Heer and Rade Belic 19
Adolf Muehl 17
A. Jurcovich, E. Franzese E M. Meoli 17
Roy Gourgi 14
Weberazevedo 13
Flavio.perona 11
Kabila 11
Tarullig 11
Igor Lazebnik 10
Alternatywa 10
Sildemar Castro 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
Sveta Marjanovic and Anastasios Tampakis 6
Hillary 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
Claus Friis 3
Michael Damb 3
Marco Meoli Alessandro Jurcovich 3
Alessandro Jurcovich E Stefano de Martino 3
Marco Meoli and Alessandro Jurcovich 3
Enzo Franzese E Michael Dambmann 3
K 3
Giovanni Acerbi and Terenzio Lazzarotto 3
Alessandro Jurcovich E Free 3
Riccardo Bertolo and Jan de Heer 2
Genivaldo Pereira 2
Ricardo Ramalho 2
Iliya Bluskov 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 Enzo Franzese 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
Marco Marco 2
Covboy 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
Alessandro Brozzetti 1

Methods used in current tables

Private tools 2242
Local search 1431
unknown1165
Simple construction 869
Dynamic programming construction 636
Multiple 608
Lex covering 258
Constructed 227
Private tool 209
Dynamic programming covering 132
Simulated annealing 118
Wheeling systems checker 4 75
Simple construction: multiple 70
Wheel generator 68
Simple construction: induced 63
Wsc v4 63
Simple construction: combined 60
Lexicographic greedy covering 57
Jymccdd programming 44
Dynamic construction 43
Local search - bluskov pdo technique 41
Korelacje_777ch__fairplay_v4 39
Dynamic programming 38
Simple construction: deleted element 31
Tabu search 27
Random greedy covering 23
Cyclic covering found by search program 20
Wang construction 19
Cyclic covering 18
Simple construction: added element to c(v-1,k-1,t) covering 18
Steiner quadruple system 16
Simple optimization 16
Sidorenko construction 16
Constructed using simulated annealing 11
Cyclic construction 10
Simple combine 10
Design is based on c (v - 1, k, t) = b - v 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
Wo - otimizador de rodas 9
Group orbit covering design 9
Nurmela and ostergard simulated annealing cover 8
Affine geometry covering 7
Nurmela-ostergard symmetric covering 7
Induced 6
Exhaustive search 6
Covering provided by rade belic 6
Shortened covering 6
Korelacje_777ch v5 6
Steiner triple system 5
See jct series a 49, 308-322 (1988) 5
Extraction/remainder 5
Sidorenko method 5
Using wsc4 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
Nurmela-ostergard simulated annealing covering design 4
Wheeling systems checker 4
777ch software + wsc v4 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
Covering provided by alex sidorenko (personal communication) 3
Using ininuga, by uros boltin 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
Wheel generator, based on jan de heer and steve muir work 2
Covering provided by john cock (personal communication) 2
Several methods (including sa) 2
Jcd 1998, pp. 21-41 2
Nurmela-ostergard simulated annealing covering 2
Hill-climb on affine orbits 2
Covering provided by dietmar pree 2
Hill-climb on cyclic orbits 2
Simple method construction 2
Ininuga 2
Metaheuristic 2
Extended covering 2
777ch software 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
From 57,8,2 1
From td(9,9) and 9*c(14,9,2,2,3) with 5 holes 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
Group theory 1
Covering 1
Privat tools 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
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
Ex 1988 1
Superfluous-element hill climb on a random greedy covering 1
Block covering 1
Ex 54 1
Ex 62 1
Chain rule (64,32,6)x(32,24,6) 1
Normal methods 1
Quadrupling a full c(10,5,5) 1
Replicate 4 columns 1
Unusual methods 1
Construction combined 1
Of,24,15,7,165 1
Of,28,10,6,2899 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__farplay_v1 1
Korelacje_777ch__fairplay_v2 1
Wsc program 1
Wheeling systems checker 4 - coming soon 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
Wheel generator and private tools 1
Not wsc v4 1
Wheel generator, covermaster and wo - otimizador de rodas 1
Using wheel generator 1
Based on work by a. tampakis 1
Wheeling systems checker, wheel generator and ininuga 1
Private tools, covermaster and wheelgenerator 1
Personal climbing method 1
Personale 1