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.

A122602 a(1) = 1; a(2) = 0; a(3) = 0; a(4) = 0; a(5) = 0; a(6) = 0; a(7) = 0; a(8) = 0; a(9) = 0; a(10) = 0; a(n) = a(n - 1) + 9a(n - 2) - 8a(n - 3) - 28a(n - 4) + 21a(n - 5) + 35a(n - 6) - 20a(n - 7) - 15a(n - 8) + 5a(n - 9) + a(n - 10) for n >= 11.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 10, 11, 65, 77, 350, 440, 1700, 2244, 7752, 10659, 33915, 48279, 144210, 211508, 600875, 904475, 2466750, 3798795, 10015005, 15737864, 40320149, 64512209, 161280568, 262255753, 641885440, 1059105390, 2544612396
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 20 2006

Keywords

Crossrefs

Cf. A066170.

Programs

  • Maple
    a[1]:=1: a[2]:=0: a[3]:=0: a[4]:=0: a[5]:=0: a[6]:=0: a[7]:=0: a[8]:=0: a[9]:=0: a[10]:=0: for n from 11 to 39 do a[n]:=a[n-1]+9*a[n-2]-8*a[n-3]-28*a[n-4]+21*a[n-5]+35*a[n-6]-20*a[n-7]-15*a[n-8]+5*a[n-9]+a[n-10] od: seq(a[n],n=1..39);
  • Mathematica
    M = {{0, 1, 0, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 1, 0, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 1, 0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 1, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 1, 0, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 1, 0, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 1, 0, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 1, 0}, {0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, {1, 5, -15, -20, 35, 21, -28, -8, 9, 1}}; v[1] = {1, 0, 0, 0, 0, 0, 0, 0, 0, 0}; v[n_] := v[n] = M.v[n - 1] a = Table[Floor[v[n][[1]]], {n, 1, 50}]
    LinearRecurrence[{1,9,-8,-28,21,35,-20,-15,5,1},{1,0,0,0,0,0,0,0,0,0},50] (* Harvey P. Dale, Dec 03 2014 *)

Formula

G.f.:((5*x^4-5*x^2+1)*(x^5-3*x^4-3*x^3+4*x^2+x-1))/((x-1)*(x^3-2*x^2-x+1)*(x^6+8*x^5+8*x^4-6*x^3-6*x^2+x+1)). [Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009]

Extensions

Edited by N. J. A. Sloane, Oct 08 2006