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Gaussian binomial coefficient [ n,12 ] for q=-10.
2

%I #20 Sep 08 2022 08:44:40

%S 1,909090909091,918273645546455463728191,

%T 917356289257199182819017528926537191,

%U 917448034060605151598548458052424151513398447191,917438859672008440688621912439351273986143166283578679347191,917439777111785551556734609501952335249856503700731106092153925870347191

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

%D 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.

%D I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.

%D M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

%H Vincenzo Librandi, <a href="/A015433/b015433.txt">Table of n, a(n) for n = 12..90</a>

%F a(n) = Product_{i=1..12} ((-10)^(n-i+1)-1)/((-10)^i-1) (by definition). - _Vincenzo Librandi_, Nov 06 2012

%t Table[QBinomial[n, 12, -10], {n, 12, 20}] (* _Vincenzo Librandi_, Nov 06 2012 *)

%o (Sage) [gaussian_binomial(n,12,-10) for n in range(12,17)] # _Zerinvary Lajos_, May 28 2009

%o (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

%K nonn,easy

%O 12,2

%A _Olivier GĂ©rard_