This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A015423 #22 Sep 08 2022 08:44:40
%S A015423 1,2731,14913991,54301841231,237244744338239,942314556807454559,
%T A015423 3920970870875818419999,15935828658299317547308959,
%U A015423 65529064844612576067331339935,267883966717492783113707839256735
%N A015423 Gaussian binomial coefficient [ n,12 ] for q=-2.
%D A015423 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 A015423 I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.
%D A015423 M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.
%H A015423 Vincenzo Librandi, <a href="/A015423/b015423.txt">Table of n, a(n) for n = 12..200</a>
%F A015423 a(n) = Product_{i=1..12} ((-2)^(n-i+1)-1)/((-2)^i-1) (by definition). - _Vincenzo Librandi_, Nov 06 2012
%t A015423 Table[QBinomial[n, 12, -2], {n, 12, 20}] (* _Vincenzo Librandi_, Nov 06 2012 *)
%o A015423 (Sage) [gaussian_binomial(n,12,-2) for n in range(12,22)] # _Zerinvary Lajos_, May 28 2009
%o A015423 (Magma) r:=12; q:=-2; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..25]]; // _Vincenzo Librandi_, Nov 06 2012
%Y A015423 Diagonal k=12 of the triangular array A015109. See there for further references and programs. - _M. F. Hasler_, Nov 04 2012
%K A015423 nonn,easy
%O A015423 12,2
%A A015423 _Olivier Gérard_