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.

A147598 Expansion of g.f. 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)).

Original entry on oeis.org

1, 1, 3, 2, 4, 3, 6, 9, 14, 23, 29, 45, 57, 88, 123, 184, 267, 382, 556, 787, 1149, 1643, 2392, 3444, 4978, 7184, 10348, 14956, 21550, 31152, 44924, 64881, 93611, 135101, 195000, 281382, 406201, 586164, 846121, 1221064, 1762399, 2543555, 3671003
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)) )); // G. C. Greubel, Oct 25 2022
    
  • Mathematica
    f[x_]= x^5 -x^4 -x^3 +x^2 -1;
    CoefficientList[Series[-1/(x^5*f[x]*f[1/x]), {x,0,50}],x]
  • SageMath
    def A147598_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1-x^2+x^3+x^4-x^5)*(1-x-x^2+x^3-x^5)) ).list()
    A147598_list(50) # G. C. Greubel, Oct 25 2022

Formula

G.f.: -1/(x^5*f(x)*f(1/x)), where f(x) = -1 +x^2 -x^3 -x^4 +x^5.
G.f.: 1/((x^5-x^4-x^3+x^2-1)*(x^5-x^3+x^2+x-1)). - Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009

Extensions

Better name (using g.f.) from Joerg Arndt, Apr 06 2018