A349874 Expansion of A(x)^3, where A(x) is g.f. of n^n (A000312).

1, 3, 15, 106, 990, 11688, 168529, 2886039, 57372984, 1299676869, 33049616319, 931991169660, 28856822050546, 972979199567826, 35480222492288493, 1391109691131953417, 58351612093156552572, 2607190821521732751855, 123613763047459102476027

Offset: 0

Author

Vaclav Kotesovec, Dec 03 2021

Keywords

• nonn

Crossrefs

Cf. A000312, A053729, A100262.

Programs

Mathematica

nmax = 20; CoefficientList[Series[(1 + Sum[n^n * x^n, {n,1,nmax}])^3, {x,0,nmax}],x]

Formula

a(n) ~ 3 * n^n.