Irregular triangle read by rows: T(n,k) is the number of unlabeled n-vertex hypergraphs (or set systems) with k hyperedges (none of which is empty), 0 <= k <= 2^n-1.
A371830
Irregular triangle read by rows: T(n,k) is the number of unlabeled n-vertex hypergraphs (or set systems) with k hyperedges (none of which is empty), 0 <= k <= 2^n-1.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =1a(7) =1a(8) =3a(9) =6a(10) =10a(11) =10a(12) =6a(13) =3a(14) =1a(15) =1a(16) =4a(17) =13a(18) =39a(19) =97a(20) =187a(21) =290a(22) =365a(23) =365a(24) =290a(25) =187a(26) =97a(27) =39a(28) =13a(29) =4
External references
- oeis: A371830