21 ≤ C(50,12,2) ≤ 23

Created by: LJCR

Method of Construction: Multiple of (25,6,2) covering

Lower Bound: Schonheim

  1  2 11 12 14 15 26 27 36 37 39 40
  1  3  9 10 18 20 26 28 34 35 43 45
  1  4  5 21 24 25 26 29 30 46 49 50
  1  6  8 16 17 19 26 31 33 41 42 44
  1  7 13 21 22 23 26 32 38 46 47 48
  2  3  4  6 13 14 27 28 29 31 38 39
  2  5 14 18 19 23 27 30 39 43 44 48
  2  7  8  9 21 25 27 32 33 34 46 50
  2  7 10 14 17 24 27 32 35 39 42 49
  2  8 14 16 20 22 27 33 39 41 45 47
  3  4 12 17 18 22 28 29 37 42 43 47
  3  5  7  8 12 16 28 30 32 33 37 41
  3 11 17 21 23 25 28 36 42 46 48 50
  3 15 19 22 24 25 28 40 44 47 49 50
  4  7  9 11 19 20 29 32 34 36 44 45
  4  8 10 15 16 23 29 33 35 40 41 48
  5  6  9 10 11 22 30 31 34 35 36 47
  5  9 13 15 17 20 30 34 38 40 42 45
  6  7 15 18 21 25 31 32 40 43 46 50
  6  9 12 20 23 24 31 34 37 45 48 49
  8 11 13 16 18 24 33 36 38 41 43 49
  9 14 16 20 21 25 34 39 41 45 46 50
 10 12 13 19 21 25 35 37 38 44 46 50