A299035 a(n) = [x^n] Product_{k=1..n} 1/(1-k^k*x).

1, 1, 21, 23980, 4896624249, 327969374429859111, 11123496833223144303532943536, 273486179312859032380857823231575174373792, 6620886635410516590847876477644821623913997428738363459941

Offset: 0

Author

Seiichi Manyama, Feb 01 2018

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..26

Crossrefs

Cf. A002109.

Cf. A007820, A298851, A299036.

Programs

Mathematica

Table[SeriesCoefficient[Product[1/(1 - k^k*x), {k, 1, n}], {x, 0, n}], {n, 0, 10}] (* Vaclav Kotesovec, Feb 02 2018 *)

Formula

a(n) ~ n^(n^2). - Vaclav Kotesovec, Feb 02 2018