A367255 a(n) = (n + 1)^(n - 2)*(3*n + 1).

1, 2, 7, 40, 325, 3456, 45619, 720896, 13286025, 280000000, 6645125311, 175432531968, 5100764198413, 161982606786560, 5579092529296875, 207165582859042816, 8250513501410645521, 350825312056827838464, 15864277746219164222455, 760217600000000000000000

Offset: 0

Author

Peter Luschny, Nov 11 2023

Keywords

• nonn

Crossrefs

Cf. A137452.

Programs

Maple

a := n -> (n + 1)^(n - 2)*(3*n + 1): seq(a(n), n = 0..19);

Mathematica

A367255[n_]:=(n+1)^(n-2)(3n+1);
Array[A367255,25,0] (* Paolo Xausa, Dec 01 2023 *)

Formula

a(n) = Sum_{k=0..n} binomial(n - 1, k - 1) * n^(n - k) * (k + 1). (See A137452.)