A015433 Gaussian binomial coefficient [ n,12 ] for q=-10.

1, 909090909091, 918273645546455463728191, 917356289257199182819017528926537191, 917448034060605151598548458052424151513398447191, 917438859672008440688621912439351273986143166283578679347191, 917439777111785551556734609501952335249856503700731106092153925870347191

Offset: 12

Author

Olivier Gérard

Keywords

• nonn
• easy

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.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 12..90

Programs

Magma

r:=12; q:=-10; [&*[(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, 12, -10], {n, 12, 20}] (* Vincenzo Librandi, Nov 06 2012 *)

Sage

[gaussian_binomial(n,12,-10) for n in range(12,17)] # Zerinvary Lajos, May 28 2009

Formula

a(n) = Product_{i=1..12} ((-10)^(n-i+1)-1)/((-10)^i-1) (by definition). - Vincenzo Librandi, Nov 06 2012