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%I #17 Jul 02 2023 14:01:11
%S 1,91,7462,605242,49031983,3971657053,321704819164,26058095733124,
%T 2110705802810605,170967170463507055,13848340811466703906,
%U 1121715605764106708446,90858964067210376612667,7359576089446900104682897
%N Gaussian binomial coefficients [ n,2 ] for q = 9.
%H Vincenzo Librandi, <a href="/A022253/b022253.txt">Table of n, a(n) for n = 2..200</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (91, -819, 729).
%F G.f.: 1/[(1-x)(1-9x)(1-81x)].
%F a(n) = Product_{i=1..2} (9^(n-i+1)-1)/(9^i-1), by definition. - _Vincenzo Librandi_, Aug 04 2016
%t Table[QBinomial[n, 2, 9], {n, 2, 20}] (* _Vincenzo Librandi_, Aug 04 2016 *)
%o (Sage) [gaussian_binomial(n,2,9) for n in range(2,16)] # _Zerinvary Lajos_, May 28 2009
%o (Magma) r:=2; q:=9; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // _Vincenzo Librandi_, Aug 04 2016
%K nonn
%O 2,2
%A _N. J. A. Sloane_.
%E Offset changed by _Vincenzo Librandi_, Aug 04 2016
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