C(19,13,3) = 6

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

Lower Bound: Bounds for fixed number of blocks

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