Triangle H(n,j) (n=1,2,3,..., j=2,3,4,...) read by rows: let X(k,l,n) := Stirling2(n,k)*Stirling2(k,l) for 1<=k<=n and 1<=l<=k. Then H(n,j)= sum_{k+l=j, 1<=k<=n and 1<=l<=k} X(k,l,n).
A136206
Triangle H(n,j) (n=1,2,3,..., j=2,3,4,...) read by rows: let X(k,l,n) := Stirling2(n,k)*Stirling2(k,l) for 1<=k<=n and 1<=l<=k. Then H(n,j)= sum_{k+l=j, 1<=k<=n and 1<=l<=k} X(k,l,n).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =4a(7) =3a(8) =1a(9) =1a(10) =7a(11) =13a(12) =19a(13) =13a(14) =6a(15) =1a(16) =1a(17) =15a(18) =40a(19) =85a(20) =96a(21) =75a(22) =35a(23) =10a(24) =1a(25) =1a(26) =31a(27) =121a(28) =335a(29) =560
External references
- oeis: A136206