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 A270247 #13 Aug 04 2024 15:13:52
%S A270247 1,7,370,41025,15637256,23079663560,127193770624285,
%T A270247 2645142169931308801,206932904585998805434690,
%U A270247 60953421285412135689567940992,67583556205239600880061198746186383,282092296203355454009618109524478429807744
%N A270247 Number of matchings in the n X n torus grid graph C_n X C_n.
%C A270247 C_{n} X C_{n} is also known as the (n,n)-torus grid graph.
%H A270247 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Matching.html">Matching</a>.
%H A270247 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TorusGridGraph.html">Torus Grid Graph</a>.
%Y A270247 Cf. A270246, A102080, A028420, A270228, A027683, A228316, A222199.
%K A270247 nonn
%O A270247 1,2
%A A270247 _Andrew Howroyd_, Mar 13 2016