A127128 Column 1 of triangle A127126.

1, 2, 9, 54, 412, 3834, 42131, 533558, 7645065, 122177706, 2153221318, 41464853266, 865908079369, 19484990264956, 469910189792853, 12089047867952058, 330423404118495975, 9561012695542004496

Offset: 1

Author

Paul D. Hanna, Jan 05 2007

Keywords

• nonn

Comments

Convolution square of A127131.

Links

• G. C. Greubel, Table of n, a(n) for n = 1..80

Crossrefs

Cf. A127126; A127131; other columns: A127127, A127129, A127130.

Programs

Mathematica

T[n_, k_]:= T[n, k]= If[k==n, 1, Coefficient[(1 +x*Sum[x^(r-k-1)*Sum[T[r, c], {c,k+1,r}], {r,k+1,n}] + x^(n+1))^(k+1), x, n-k]]; Table[T[n, 1], {n, 1, 20}] (* G. C. Greubel, Jan 28 2020 *)