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.

A060962 Expansion of (1+x^2)*(1+x^5)/( Product_{j=1..7} (1-x^j) ).

Original entry on oeis.org

1, 1, 3, 4, 7, 11, 17, 25, 36, 50, 69, 93, 125, 163, 213, 272, 346, 435, 543, 671, 825, 1005, 1218, 1466, 1756, 2090, 2478, 2921, 3430, 4009, 4669, 5414, 6259, 7207, 8274, 9468, 10803, 12289, 13944, 15777, 17809, 20052, 22528, 25249, 28243, 31522, 35115, 39041, 43327, 47995, 53078
Offset: 0

Views

Author

N. J. A. Sloane, May 05 2002

Keywords

References

  • G. E. Andrews, P. Paule and A. Riese, MacMahon's Partition Analysis VIII: Plane partition diamonds, Advances Applied Math., 27 (2001), 231-242 (Cor. 2.1, n=2).

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 55); Coefficients(R!( (1+x^2)*(1+x^5)/( &*[1-x^j: j in [1..7]] ) )); // G. C. Greubel, Jan 15 2020
    
  • Maple
    seq(coeff(series((1+x^2)*(1+x^5)/(mul(1-x^j, j=1..7)), x, n+1), x, n), n = 0..55); # G. C. Greubel, Jan 15 2020
  • Mathematica
    Table[SeriesCoefficient[(1+x^2)*(1+x^5)/(1-x)/(1-x^2)/(1-x^3)/(1-x^4)/(1-x^5)/(1-x^6)/(1-x^7),{x,0,n}],{n,0,55}] (* Vaclav Kotesovec, Oct 01 2012 *)
  • PARI
    Vec((1+x^2)*(1+x^5)/(1-x)/(1-x^2)/(1-x^3)/(1-x^4)/(1-x^5)/(1-x^6)/(1-x^7) +O(x^55)) \\ Charles R Greathouse IV, Sep 27 2012
    
  • Sage
    def A060962_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1+x^2)*(1+x^5)/(product(1-x^j for j in (1..7))) ).list()
    A060962_list(55) # G. C. Greubel, Jan 15 2020

Formula

a(n) = 1 - 263117*n/1814400 + 109537*n^2/907200 + 97*n^3/4320 + 127*n^4/72576 + n^5/14400 + n^6/907200 + 4/7*floor(n/7) + 1/3*floor(n/6) + 2/25*floor(n/5) - 11/162*floor(n/3) + (73/192 + 5*n/96)*floor(n/2) + 1/7*floor((1+n)/7) - 1/6*floor((1+n)/6) + 4/25*floor((1+n)/5) + (53/162 + n/54)*floor((1+n)/3) + 3/7*floor((2+n)/7) - 4/25*floor((2+n)/5) + 2/7*floor((3+n)/7) + 8/25*floor((3+n)/5) + 1/7*floor((4+n)/7) + 3/7*floor((5+n)/7). - Vaclav Kotesovec, Sep 29 2012

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
Showing 1-2 of 2 results.