A289955 Number of permutations of [n] having exactly seven nontrivial cycles.

135135, 11486475, 583783200, 23434451040, 828052325100, 27221423409180, 859752405431920, 26617555964919920, 818486200464162230, 25221598500336187950, 783666055857936771520, 24658659357394687609600, 788174700361283653718300, 25647112073453527447490700

Offset

14,1

Comments

A nontrivial cycle has size > 1.

Links

Alois P. Heinz, Table of n, a(n) for n = 14..450

Wikipedia, Permutation

Formula

E.g.f.: (-log(1-x)-x)^7/7!*exp(x).

Mathematica

Drop[CoefficientList[Series[(-Log[1 - x] - x)^7/7!*Exp[x] , {x, 0, 50}], x] * Table[k !, {k, 0, 50}] , 14] (* Indranil Ghosh, Jul 16 2017 *)

Prog

(PARI) x = 'x + O('x^30); Vec(serlaplace((-log(1-x)-x)^7/7!*exp(x))) \\ Michel Marcus, Jul 16 2017

Crossrefs

Column k=7 of A136394.

Sequence in context: A271767 A104440 A290036 * A263891 A360662 A235209

Adjacent sequences: A289952 A289953 A289954 * A289956 A289957 A289958

Keyword

nonn

Author

Alois P. Heinz, Jul 16 2017

Status

approved