C(19,15,5) = 9

Method of Construction: simple construction: added element to c(v-1,k-1,t) covering

Lower Bound: Mills, Covering Designs I, 1979

  2  3  4  5  6  7  8  9 10 11 12 13 14 15 19
  2  3  4  5  6  7  8  9 10 11 12 13 16 17 19
  1  2  3  4  5  6  7  8  9 10 11 12 13 18 19
  1  2  3  4  5  6  7  8  9 14 15 16 17 18 19
  1  2  3  4  5  6  7 10 11 14 15 16 17 18 19
  1  2  3  4  5  6  7 12 13 14 15 16 17 18 19
  1  2  3  8  9 10 11 12 13 14 15 16 17 18 19
  1  4  5  8  9 10 11 12 13 14 15 16 17 18 19
  1  6  7  8  9 10 11 12 13 14 15 16 17 18 19