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.

A078045 Expansion of (1-x)/(1+x+x^2-2*x^3).

Original entry on oeis.org

1, -2, 1, 3, -8, 7, 7, -30, 37, 7, -104, 171, -53, -326, 721, -501, -872, 2815, -2945, -1614, 10189, -14465, 1048, 33795, -63773, 32074, 99289, -258909, 223768, 233719, -975305, 1189122, 253621, -3393353, 5517976, -1617381, -10687301, 23340634, -15888095, -28827141, 91396504
Offset: 0

Views

Author

N. J. A. Sloane, Nov 17 2002

Keywords

Crossrefs

First differences of A077975.

Programs

  • Mathematica
    CoefficientList[Series[(1-x)/(1+x+x^2-2*x^3),{x,0,40}],x] (* or *) LinearRecurrence[{-1,-1,2},{1,-2,1},50] (* Harvey P. Dale, Jun 12 2016 *)

Formula

Recurrence: a(n) = 2a(n-3) - a(n-2) - a(n-1), starting 1,-2,1. - Ralf Stephan, Aug 18 2013