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.

A015413 Gaussian binomial coefficient [ n,11 ] for q=-8.

Original entry on oeis.org

1, -7635497415, 66629509457629850745, -571227449525600988055816521095, 4908004671908135948969747939905903872633, -42158152544207284340561914581652169948472972883335
Offset: 11

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References

  • J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.
  • I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
  • M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Programs

  • Magma
    r:=11; q:=-8; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 06 2012
  • Mathematica
    Table[QBinomial[n, 11, -8], {n, 11, 20}] (* Vincenzo Librandi, Nov 06 2012 *)
  • Sage
    [gaussian_binomial(n,11,-8) for n in range(11,17)] # Zerinvary Lajos, May 28 2009
    

Formula

a(n) = Product_{i=1..11} ((-8)^(n-i+1)-1)/((-8)^i-1) (by definition). - Vincenzo Librandi, Nov 06 2012