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 A367528 #26 Jul 06 2024 10:03:06
%S A367528 1,5,136,16448,8390656,17179934720,140737496743936,
%T A367528 4611686019501129728,604462909807864343166976,
%U A367528 316912650057057631849152512000,664613997892457937028364282443595776,5575186299632655785385110159782807787798528,187072209578355573530071668259090783432992763150336
%N A367528 The number of ways of tiling the n X n grid up to diagonal and antidiagonal reflections by a tile that is fixed under 180-degree rotations but is not fixed under either reflection.
%H A367528 Peter Kagey, <a href="/A367528/a367528.pdf">Illustration of a(2)=5</a>
%H A367528 Peter Kagey and William Keehn, <a href="https://arxiv.org/abs/2311.13072">Counting tilings of the n X m grid, cylinder, and torus</a>, arXiv: 2311.13072 [math.CO], 2023. See also <a href="https://cs.uwaterloo.ca/journals/JIS/VOL27/Kagey/kagey6.html">J. Int. Seq.</a>, (2024) Vol. 27, Art. No. 24.6.1, pp. A-6, A-9.
%F A367528 a(2m-1) = 2^(2m^2 - 4m - 1)*(4^m + 4^m^2).
%F A367528 a(2m) = (4^m^2 + 16^m^2)/4.
%t A367528 Table[{2^(2 m^2 - 4 m - 1) (4^m + 4^m^2), (4^m^2 + 16^m^2)/4}, {m, 1, 5}] // Flatten
%Y A367528 Cf. A367524, A367526, A367527, A367529.
%K A367528 nonn
%O A367528 1,2
%A A367528 _Peter Kagey_, Dec 10 2023