%I #28 Sep 08 2022 08:44:39
%S 1,9091,91828191,917364637191,9174563736547191,91744720010017447191,
%T 917448117456547208447191,9174480257209191175298447191,
%U 91744803489448201844894398447191
%N Gaussian binomial coefficient [ n,4 ] 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="/A015298/b015298.txt">Table of n, a(n) for n = 4..200</a>
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (9091,9181910,-918191000,-9091000000,10000000000).
%F G.f.: -x^4 / ( (x-1)*(10*x+1)*(1000*x+1)*(100*x-1)*(10000*x-1) ). - _R. J. Mathar_, Aug 03 2016
%t Table[QBinomial[n, 4, -10], {n, 4, 20}] (* _Vincenzo Librandi_, Oct 28 2012 *)
%o (Sage) [gaussian_binomial(n,4,-10) for n in range(4,13)] # _Zerinvary Lajos_, May 27 2009
%o (Magma) r:=4; q:=-10; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..25]]; // _Vincenzo Librandi_, Aug 03 2016
%K nonn,easy
%O 4,2
%A _Olivier GĂ©rard_, Dec 11 1999