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.

Showing 1-2 of 2 results.

A147593 Expansion of 1/(1 - x + x^3 - 3*x^4 + x^5 - x^7 + x^8).

Original entry on oeis.org

1, 1, 1, 0, 2, 3, 5, 3, 6, 8, 16, 16, 24, 28, 50, 61, 91, 109, 170, 220, 327, 415, 607, 800, 1164, 1536, 2192, 2928, 4172, 5616, 7921, 10705, 15049, 20460, 28638, 39027, 54453, 74451, 103662, 141996, 197288, 270704, 375632, 516096, 715258, 983661, 1362091
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/((1+x^3-x^4)*(1-x-x^4)) )); // G. C. Greubel, Oct 25 2022
    
  • Mathematica
    f[x_]= x^4-x^3-1; CoefficientList[Series[-1/(x^4*f[x]*f[1/x]), {x,0,50}], x]
  • SageMath
    def A147593_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1+x^3-x^4)*(1-x-x^4)) ).list()
    A147593_list(50) # G. C. Greubel, Oct 25 2022

Formula

G.f.: -1/(x^4*f(x)*f(1/x)), where f(x) = -1 - x^3 + x^4.
G.f.: 1/((1+x^3-x^4)*(1-x-x^4)). - Colin Barker, Nov 04 2012

Extensions

Edited by Joerg Arndt and Colin Barker, Nov 04 2012.

A147592 Expansion of 1/(1 + x - x^2 - 3*x^3 - x^4 + x^5 + x^6).

Original entry on oeis.org

1, -1, 2, 0, 0, 4, -2, 5, 3, 0, 12, 0, 12, 16, 5, 35, 18, 36, 64, 40, 110, 105, 135, 240, 216, 384, 472, 560, 905, 999, 1458, 1960, 2368, 3500, 4302, 5805, 7947, 9936, 13860, 17920, 23588, 32096, 41229, 55755, 73570, 96460, 129920, 169680, 226206, 300369
Offset: 0

Views

Author

Roger L. Bagula, Nov 08 2008

Keywords

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 60); Coefficients(R!( 1/((1+x-x^3)*(1-x^2-x^3)) )); // G. C. Greubel, Oct 25 2022
    
  • Mathematica
    f[x_]= x^3-x-1; CoefficientList[Series[-1/(x^3*f[x]*f[1/x]), {x,0,60}], x]
    LinearRecurrence[{-1,1,3,1,-1,-1},{1,-1,2,0,0,4},60] (* Harvey P. Dale, Sep 23 2020 *)
  • SageMath
    def A147592_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( 1/((1+x-x^3)*(1-x^2-x^3)) ).list()
    A147592_list(60) # G. C. Greubel, Oct 25 2022

Formula

G.f.: -1/(x^3*f(x)*f(1/x)), where f(x) = -1 - x + x^3.
G.f.: 1/((1+x-x^3)*(1-x^2-x^3)). - Colin Barker, Nov 04 2012

Extensions

Edited by Joerg Arndt and Colin Barker, Nov 04 2012
Showing 1-2 of 2 results.