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.

A069957 Expansion of 1/((1-x)^2*(1-x^2)^2*(1-x^3)*(1-x^4)^2*(1-x^5)).

Original entry on oeis.org

1, 2, 5, 9, 18, 30, 51, 79, 124, 183, 270, 382, 540, 740, 1010, 1347, 1789, 2333, 3028, 3873, 4932, 6205, 7772, 9637, 11901, 14571, 17770, 21512, 25948, 31098, 37143, 44113, 52226, 61522, 72258, 84489, 98519, 114418, 132540, 152976, 176139, 202141
Offset: 0

Views

Author

N. J. A. Sloane, May 05 2002

Keywords

Crossrefs

Cf. A069950.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 60); Coefficients(R!( (1-x^3)*(1-x^5)/(&*[1-x^j: j in [1..5]])^2 )); // G. C. Greubel, Aug 17 2022
    
  • Mathematica
    CoefficientList[Series[1/((1 - x)^2 (1 - x^2)^2 (1 - x^3) (1 - x^4)^2 (1 - x^5)), {x, 0, 60}], x] (* Vincenzo Librandi, Sep 05 2016 *)
  • Sage
    def A069957_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-x^3)*(1-x^5)/(product(1-x^j for j in (1..5)))^2 ).list()
    A069957_list(60) # G. C. Greubel, Aug 17 2022

Formula

G.f.: (1-x^3)*(1-x^5)/( Product_{j=1..5} 1-x^j )^2. - G. C. Greubel, Aug 17 2022