A322514 a(n) = [x^(n^2)] (Sum_{k=0..2*n} (k+1)*x^k)^n.

1, 2, 35, 1624, 169653, 30961656, 8792309747, 3592089777760, 1998565555891049, 1454040182726241040, 1340732073013968993771, 1528443066775450331625912, 2111332024387378632991315275, 3475577885419591506890414078832

Offset: 0

Author

Seiichi Manyama, Dec 13 2018

Keywords

• nonn

Crossrefs

Cf. A084609, A286928.

Programs

Mathematica

f[n_] := Coefficient[Expand[Sum[(k+1)*x^k ,{k, 0, 2n}]^n, x], x, n^2]; Array[f, 15, 0] (* Amiram Eldar, Dec 13 2018 *)

PARI

{a(n) = polcoeff((sum(k=0, 2*n, (k+1)*x^k))^n, n^2, x)}