C(13,9,3) = 6

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

Lower Bound: Bounds for fixed number of blocks

  2  3  4  5  6  7  8  9 13
  2  3  4  5  6  7 10 11 13
  1  2  3  4  5  6  7 12 13
  1  2  3  8  9 10 11 12 13
  1  4  5  8  9 10 11 12 13
  1  6  7  8  9 10 11 12 13