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 A360922 #9 Feb 16 2025 08:34:04 %S A360922 1,2,2,4,14,4,8,98,98,8,16,686,2398,686,16,32,4802,58670,58670,4802, %T A360922 32,64,33614,1435414,5015972,1435414,33614,64,128,235298,35118638, %U A360922 428816558,428816558,35118638,235298,128,256,1647086,859207558,36659327366,128091434266,36659327366,859207558,1647086,256 %N A360922 Array read by antidiagonals: T(m,n) is the number of acyclic orientations in the grid graph P_m X P_n. %H A360922 Andrew Howroyd, <a href="/A360922/b360922.txt">Table of n, a(n) for n = 1..253</a> (first 22 antidiagonals). %H A360922 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GridGraph.html">Grid Graph</a>. %H A360922 Wikipedia, <a href="https://en.wikipedia.org/wiki/Acyclic_orientation">Acyclic orientation</a>. %F A360922 T(m,n) = T(n,m). %e A360922 Array begins: %e A360922 ===================================================== %e A360922 m\n| 1 2 3 4 5 ... %e A360922 ---+------------------------------------------------- %e A360922 1 | 1 2 4 8 16 ... %e A360922 2 | 2 14 98 686 4802 ... %e A360922 3 | 4 98 2398 58670 1435414 ... %e A360922 4 | 8 686 58670 5015972 428816558 ... %e A360922 5 | 16 4802 1435414 428816558 128091434266 ... %e A360922 6 | 32 33614 35118638 36659327366 38261306901842 ... %e A360922 ... %Y A360922 Main diagonal is A080690. %Y A360922 Rows 1..2 are A000079(n-1), A109808. %Y A360922 Cf. A116469 (spanning trees), A178435, A207868 (unlabeled colorings). %K A360922 nonn,tabl %O A360922 1,2 %A A360922 _Andrew Howroyd_, Mar 07 2023