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%I #17 Sep 08 2022 08:44:46
%S 1,1555,2072815,2698853335,3500412775495,4537117983992551,
%T 5880230843762528935,7620806375898728694055,9876570938882852540717095,
%U 12800037205947411879866507815,16588848493045381066264096333351
%N Gaussian binomial coefficients [ n,4 ] for q = 6.
%H Vincenzo Librandi, <a href="/A022222/b022222.txt">Table of n, a(n) for n = 4..200</a>
%F G.f.: x^4/((1-x)*(1-6*x)*(1-36*x)*(1-216*x)*(1-1296*x)). - _Vincenzo Librandi_, Aug 11 2016
%F a(n) = Product_{i=1..4} (6^(n-i+1)-1)/(6^i-1), by definition. - _Vincenzo Librandi_, Aug 11 2016
%t Table[QBinomial[n, 4, 6], {n, 4, 20}] (* _Vincenzo Librandi_, Aug 11 2016 *)
%o (Sage) [gaussian_binomial(n,4,6) for n in range(4,15)] # _Zerinvary Lajos_, May 27 2009
%o (Magma) r:=4; q:=6; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // _Vincenzo Librandi_, Aug 11 2016
%o (PARI) r=4; q=6; for(n=r,30, print1(prod(j=1,r,(1-q^(n-j+1))/(1-q^j)), ", ")) \\ _G. C. Greubel_, Jun 07 2018
%K nonn,easy
%O 4,2
%A _N. J. A. Sloane_
%E Offset changed by _Vincenzo Librandi_, Aug 11 2016
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