28 ≤ C(25,13,4) ≤ 30

Created by: Andrei Ochmat

Lower Bound: Theorem 2.1 of Mills and Mullin; r=2

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