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 A360063 #14 Feb 18 2023 08:07:35 %S A360063 0,0,3,0,24,1152,0,354,436416,2595450592,0,8138,129422880 %N A360063 Triangle read by rows: T(m,n) is the number of Hamiltonian cycles in the graph whose nodes are the integer lattice points (x,y) with 0 <= x < m and 0 <= y < n, and with an edge between two nodes if there is no other integer lattice point on the line segment between them; 1 <= n <= m. %C A360063 The graph represents tree-to-tree visibility in Euclid's orchard. It also appears in A247943, A247944, and A360062. Is there an established name for it? %H A360063 Wikipedia, <a href="https://en.wikipedia.org/wiki/Euclid's_orchard">Euclid's orchard</a>. %e A360063 Triangle begins: %e A360063 m\n| 1 2 3 4 5 %e A360063 ---+------------------------------- %e A360063 1 | 0 %e A360063 2 | 0 3 %e A360063 3 | 0 24 1152 %e A360063 4 | 0 354 436416 2595450592 %e A360063 5 | 0 8138 129422880 ? ? %Y A360063 Cf. A247943, A247944, A321172, A360062. %K A360063 nonn,tabl,more %O A360063 1,3 %A A360063 _Pontus von Brömssen_, Jan 24 2023