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.

A228997 Total sum of the 7th powers of lengths of ascending runs in all permutations of [n].

Original entry on oeis.org

0, 1, 130, 2706, 32226, 315684, 2961498, 28544040, 291590754, 3194874900, 37656861354, 477018980928, 6477756701010, 94006723773564, 1453236561824250, 23855684885059944, 414605141516228418, 7607828522859788580, 147012653519046471114, 2984603478905797978320
Offset: 0

Views

Author

Alois P. Heinz, Sep 10 2013

Keywords

Crossrefs

Column k=7 of A229001.

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<4, [0, 1, 130, 2706][n+1],
          ((16*n^3-38*n^2-16*n+278) *a(n-1)
          -(8*n^4-3*n^3-101*n^2+623*n-512) *a(n-2)
          +2*(n-2)*(8*n^3-32*n^2+134*n-95) *a(n-3)
          -(n-2)*(n-3)*(8*n^2-37*n+44) *a(n-4)) /(8*n^2-27*n+24))
        end:
    seq(a(n), n=0..30);
  • Mathematica
    With[{nn=20},CoefficientList[Series[(Exp[x](42x^5+210x^4+280x^3+126x-126)+x+126)/(x-1)^2,{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jul 31 2021 *)

Formula

E.g.f.: (exp(x)*(42*x^5+210*x^4+280*x^3+126*x-126)+x+126)/(x-1)^2.
a(n) ~ n! * (532*exp(1)+127)*n. - Vaclav Kotesovec, Sep 12 2013