Triangular array read by rows: T(n,k) is the number of ways to partition an n-set into exactly k blocks and then partially order the blocks, n>=1, 1<=k<=n.
A247231
Triangular array read by rows: T(n,k) is the number of ways to partition an n-set into exactly k blocks and then partially order the blocks, n>=1, 1<=k<=n.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =1a(4) =9a(5) =19a(6) =1a(7) =21a(8) =114a(9) =219a(10) =1a(11) =45a(12) =475a(13) =2190a(14) =4231a(15) =1a(16) =93a(17) =1710a(18) =14235a(19) =63465a(20) =130023a(21) =1a(22) =189a(23) =5719a(24) =76650a(25) =592340a(26) =2730483a(27) =6129859a(28) =1a(29) =381
External references
- oeis: A247231