cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A289957 Number of permutations of [n] having exactly nine nontrivial cycles.

Original entry on oeis.org

34459425, 4583103525, 353553700500, 20941727706900, 1063956789420525, 49122916648430625, 2133284602385096160, 89095866141017736000, 3632887356673057858375, 146162134100332940264675, 5846991791902793693661500, 233881907399101905866222300
Offset: 18

Views

Author

Alois P. Heinz, Jul 16 2017

Keywords

Comments

A nontrivial cycle has size > 1.

Crossrefs

Column k=9 of A136394.

Programs

  • Mathematica
    Drop[CoefficientList[Series[(-Log[1 - x] - x)^9/9!*Exp[x] , {x, 0, 50}], x] * Table[k !, {k, 0, 50}] , 18] (* Indranil Ghosh, Jul 16 2017 *)
  • PARI
    x = 'x + O('x^30); Vec(serlaplace((-log(1-x)-x)^9/9!*exp(x))) \\ Michel Marcus, Jul 16 2017

Formula

E.g.f.: (-log(1-x)-x)^9/9!*exp(x).