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.

A070558 Number of two-rowed partitions of length 5.

Original entry on oeis.org

1, 1, 3, 5, 10, 16, 28, 42, 68, 100, 151, 215, 312, 432, 605, 821, 1117, 1485, 1977, 2581, 3371, 4335, 5566, 7060, 8938, 11196, 13994, 17338, 21426, 26280, 32152, 39074, 47369, 57093, 68637, 82097, 97955, 116339, 137849, 162665, 191507
Offset: 0

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Author

N. J. A. Sloane, May 07 2002

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> (Matrix(35, (i,j)-> if (i=j-1) then 1 elif j=1 then [1, 2, 0, -1, -3, -2, -2, 3, 7, 5, 1, -4, -8, -11, -1, 5, 9, 9, 5, -1, -11, -8, -4, 1, 5, 7, 3, -2, -2, -3, -1, 0, 2, 1, -1][i] else 0 fi)^n)[1,1]: seq(a(n), n=0..40); # Alois P. Heinz, Jul 31 2008
  • Mathematica
    m = 5; n = 45; gf = 1/((1-x)*Product[1-x^k, {k, 2, m}]^2*(1-x^(m+1))) + O[x]^n; CoefficientList[gf, x] (* Jean-François Alcover, Jul 17 2015 *)

Formula

G.f.: 1/((1-x)*((1-x^2)*...*(1-x^m))^2*(1-x^(m+1))) for m = 5.