lower bound = 75

C(30,4,2) = 75

Method of Construction: mills, jcta 13 (1972) pp. 55-78.

Lower Bound: Schonheim

  1  8 16 23
  2  9 17 24
  3 10 18 25
  4 11 19 26
  5 12 20 27
  6 13 21 28
  7 14 22 29
  8 15 23 30
  1  9 16 24
  2 10 17 25
  3 11 18 26
  4 12 19 27
  5 13 20 28
  6 14 21 29
  7 15 22 30
  1  3 15 20
  2  4 16 21
  3  5 17 22
  4  6 18 23
  5  7 19 24
  6  8 20 25
  7  9 21 26
  8 10 22 27
  9 11 23 28
 10 12 24 29
 11 13 25 30
  1 12 14 26
  2 13 15 27
  3 14 16 28
  4 15 17 29
  5 16 18 30
  1  6 17 19
  2  7 18 20
  3  8 19 21
  4  9 20 22
  5 10 21 23
  6 11 22 24
  7 12 23 25
  8 13 24 26
  9 14 25 27
 10 15 26 28
 11 16 27 29
 12 17 28 30
  1 13 18 29
  2 14 19 30
  1  2  5 11
  2  3  6 12
  3  4  7 13
  4  5  8 14
  5  6  9 15
  6  7 10 16
  7  8 11 17
  8  9 12 18
  9 10 13 19
 10 11 14 20
 11 12 15 21
 12 13 16 22
 13 14 17 23
 14 15 18 24
 15 16 19 25
 16 17 20 26
 17 18 21 27
 18 19 22 28
 19 20 23 29
 20 21 24 30
  1 21 22 25
  2 22 23 26
  3 23 24 27
  4 24 25 28
  5 25 26 29
  6 26 27 30
  1  7 27 28
  2  8 28 29
  3  9 29 30
  1  4 10 30