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%I #24 Sep 08 2022 08:44:39
%S 1,-58266480,3677897920745140,-230677643550873536294640,
%T 14475186854407942097510802411322,
%U -908294062111964496034866469968025332240
%N Gaussian binomial coefficient [ n,7 ] for q=-13.
%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="/A015355/b015355.txt">Table of n, a(n) for n = 7..130</a>
%H <a href="/index/Ga#Gaussian_binomial_coefficients">Index entries related to Gaussian binomial coefficients</a>.
%F a(n) = Product_{i=1..7} ((-13)^(n-i+1)-1)/((-13)^i-1). - _M. F. Hasler_, Nov 03 2012
%t Table[QBinomial[n, 7, -13], {n, 7, 16}] (* _Vincenzo Librandi_, Nov 02 2012 *)
%o (Sage) [gaussian_binomial(n,7,-13) for n in range(7,13)] # _Zerinvary Lajos_, May 27 2009
%o (Magma) r:=7; q:=-13; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..15]]; // _Vincenzo Librandi_, Nov 02 2012
%o (PARI) A015355(n,r=7,q=-13)=prod(i=1,r,(q^(n-i+1)-1)/(q^i-1)) \\ _M. F. Hasler_, Nov 03 2012
%Y Cf. Gaussian binomial coefficients [n,r] for q=-13: A015265 (r=2), A015286 (r=3), A015303 (r=4), A015321 (r=5), A015337 (r=6), A015370 (r=8), A015385 (r=9), A015402 (r=10), A015422 (r=11), A015438 (r=12). - _M. F. Hasler_, Nov 03 2012
%K sign,easy
%O 7,2
%A _Olivier Gérard_
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