A055867 Fourth column of triangle A055864.

0, 0, 0, 64, 750, 10584, 175616, 3359232, 72900000, 1771561000, 47692136448, 1409582685888, 45392319784448, 1582328671875000, 59373627899904000, 2386420683693101056, 102303226385042448384, 4659806991485780193672

Offset

1,4

Links

Table of n, a(n) for n=1..18.

Formula

a(i)=0 for i=1, 2, 3; a(n) = n^3*(n+1)^(n-4), n >= 4.

E.g.f.: (9*W(-x)^2-14*W(-x)^3+3*W(-x)^4-9*x^2-32*x^3-81*x^4)/(72*x), W(x) principal branch of Lambert's function.

Maple

A055867:=n->n^3*(n+1)^(n-4): 0, 0, 0, seq(A055867(n), n=4..30); # Wesley Ivan Hurt, Jan 27 2017

Crossrefs

a(n)=A055864(n, 4). Cf. A000272, A055865, A055070, A055866, A055858.

Sequence in context: A108538 A195593 A221753 * A304346 A316217 A305641

Adjacent sequences: A055864 A055865 A055866 * A055868 A055869 A055870

Keyword

nonn,easy

Author

Wolfdieter Lang, Jun 20 2000

Status

approved