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 A340352 #23 Jan 06 2021 04:23:53
%S A340352 1,192,4542720,12116689944576,3544863978266468352000,
%T A340352 112387469554685044937510092800000,
%U A340352 383669915612621265759587438135691539652804608,140496256399491641572818822014023027580848616806252629983232
%N A340352 Number of spanning trees of odd Aztec diamond OD_n.
%C A340352 R. P. Stanley conjectured that the even Aztec diamond has exactly four times as many spanning trees as the odd Aztec diamond. This conjecture was first proved by D. E. Knuth.
%C A340352 *
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%C A340352 OD_1 OD_2 OD_3
%H A340352 D. E. Knuth, <a href="https://arxiv.org/abs/math/9501234">Aztec Diamonds, Checkerboard Graphs, and Spanning Trees</a>, arXiv:math/9501234 [math.CO], 1995; J. Alg. Combinatorics 6 (1997), 253-257.
%F A340352 a(n) = 4^(2*(n-1)) * A340166(n) = 4^(2*(n-1)*n) * Product_{1<=j,k<=n-1} (1 - sin(j*Pi/(2*n))^2 * sin(k*Pi/(2*n))^2).
%F A340352 a(n) ~ Gamma(1/4) * exp(8*G*n^2/Pi) / (Pi^(3/4) * sqrt(n) * 2^(2*n + 2)), where G is Catalan's constant A006752. - _Vaclav Kotesovec_, Jan 06 2021
%o A340352 (PARI) default(realprecision, 120);
%o A340352 {a(n) = round(4^(2*(n-1)*n)*prod(j=1, n-1, prod(k=1, n-1, 1-(sin(j*Pi/(2*n))*sin(k*Pi/(2*n)))^2)))}
%Y A340352 Cf. A007725 (even Aztec diamond), A340166, A340185 (halved Aztec diamond HOD_n).
%K A340352 nonn
%O A340352 1,2
%A A340352 _Seiichi Manyama_, Jan 05 2021