A346187 a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^3 * a(k) * a(n-k-1).

1, 1, 9, 279, 20655, 2997405, 753171615, 300907367775, 179603100388215, 152724638158940925, 178223093773584811875, 276909379421415142992975, 558708999223935430219474125, 1433526175506213101913925750425, 4594607165137022427482460137390625, 18114938314838093950739712451059177375

Offset

0,3

Links

Table of n, a(n) for n=0..15.

Mathematica

a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^3 a[k] a[n - k - 1], {k, 0, n - 1}]; Table[a[n], {n, 0, 15}]

Crossrefs

Cf. A001059, A001147, A181543, A336195, A346186.

Sequence in context: A330604 A336259 A177107 * A012234 A012141 A328123

Adjacent sequences: A346184 A346185 A346186 * A346188 A346189 A346190

Keyword

nonn

Author

Ilya Gutkovskiy, Jul 09 2021

Status

approved