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.

A170975 Expansion of Product_{i=0..m-1} (1 + x^(4*i+1)) for m = 12.

Original entry on oeis.org

1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 2, 1, 0, 1, 2, 1, 0, 1, 3, 2, 0, 1, 3, 3, 1, 1, 4, 4, 1, 1, 4, 5, 2, 1, 5, 7, 3, 1, 5, 8, 5, 2, 6, 10, 6, 1, 5, 12, 9, 2, 5, 13, 11, 3, 4, 14, 15, 5, 4, 15, 17, 7, 4, 15, 21, 10, 4, 15, 23, 13, 4, 15, 27, 17, 5, 14, 28, 21, 6, 13, 31, 26, 8, 12, 31, 30, 11, 11
Offset: 0

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Author

N. J. A. Sloane, Aug 29 2010

Keywords

Crossrefs

Programs

  • Magma
    m:=12; R:=PowerSeriesRing(Integers(), 100); Coefficients(R!( (&*[1+x^(4*j+1): j in [0..m-1]]) )); // G. C. Greubel, Feb 24 2019
    
  • Maple
    seq(coeff(mul((1+x^(4*i+1)),i=0..11),x,n),n=0..100); # Nathaniel Johnston, Jun 24 2011
  • Mathematica
    With[{m=12}, CoefficientList[Series[Product[(1 + x^(4*j+1)), {j,0,m-1}], {x,0,100}],x]] (* G. C. Greubel, Feb 24 2019 *)
  • PARI
    m=12; my(x='x+O('x^(100))); Vec(prod(j=0,m-1, 1+x^(4*j+1) )) \\ G. C. Greubel, Feb 24 2019
    
  • Sage
    m=12; ( prod(1+x^(4*j+1) for j in (0..m-1)) ).series(x, 100).coefficients(x, sparse=False) # G. C. Greubel, Feb 24 2019

Formula

a(n) = a(276-n). - Rick L. Shepherd, Mar 01 2013

Extensions

Typo in Maple program fixed and b-file extended 9 terms by Rick L. Shepherd, Mar 01 2013