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.

A109786 Expansion of -(x+2*x^2+3*x^3-1+5*x^4)/((x+1)*(x^2-3*x+1)*(1+x^2)).

Original entry on oeis.org

1, 1, 1, 1, 1, 5, 13, 33, 85, 225, 589, 1541, 4033, 10561, 27649, 72385, 189505, 496133, 1298893, 3400545, 8902741, 23307681, 61020301, 159753221, 418239361, 1094964865, 2866655233, 7505000833, 19648347265, 51440040965, 134671775629
Offset: 0

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Author

Creighton Dement, Aug 14 2005

Keywords

Comments

Floretion Algebra Multiplication Program, FAMP Code: 4jbaseksumseq[ + .25'i + .25i' + .25'ii' + .25'jj' + .25'kk' + .25'jk' + .25'kj' + .25e], sumtype: Y[15],inty[ * ]

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-(x+2x^2+3x^3-1+5x^4)/((x+1)(x^2-3x+1)(1+x^2)),{x,0,30}],x] (* or *) LinearRecurrence[{2,1,1,2,-1},{1,1,1,1,1},40] (* Harvey P. Dale, Apr 14 2015 *)

Formula

a(0)=1, a(1)=1, a(2)=1, a(3)=1, a(4)=1, a(n)=2*a(n-1)+a(n-2)+a(n-3)+ 2*a(n-4)- a(n-5). - Harvey P. Dale, Apr 14 2015