A346186 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n-1,k)^3 * a(k) * a(n-k-1).

1, 1, 2, 12, 132, 2664, 86328, 4257504, 302249232, 29749088160, 3929593244256, 678729769735680, 149951093054923584, 41593439995316826624, 14254785976456164378240, 5952723682598023085466624, 2992204352832467277009072384, 1791038631707465961597691673088

Offset

0,3

Links

Table of n, a(n) for n=0..17.

Mathematica

a[0] = 1; a[n_] := a[n] = Sum[Binomial[n - 1, k]^3 a[k] a[n - k - 1], {k, 0, n - 1}]; Table[a[n], {n, 0, 17}]

Crossrefs

Cf. A000142, A132228, A181543, A346185, A346187.

Sequence in context: A208830 A132472 A179420 * A080487 A077696 A326361

Adjacent sequences: A346183 A346184 A346185 * A346187 A346188 A346189

Keyword

nonn

Author

Ilya Gutkovskiy, Jul 09 2021

Status

approved