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 A307025 #10 Feb 16 2025 08:33:55 %S A307025 0,0,0,0,2,56,0,4,374,14980,0,8,2664,302844,19005336,0,12,17556, %T A307025 6530656,1248702804,278982789260,0,18,121838,151793054 %N A307025 Number of (undirected) paths in the m X n knight graph (triangle read by rows with m = 1..n and n = 1..). %H A307025 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/GraphPath.html">Graph Path</a> %H A307025 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/KnightGraph.html">Knight Graph</a> %F A307025 a(1, n) = 0. %F A307025 a(2, n) = (1 - (-1)^n + 2*n*(n - 2))/4 for n > 1. %F A307025 a(n, n) = A288033(n). %e A307025 0; %e A307025 0, 0; %e A307025 0, 2, 56; %e A307025 0, 4, 374, 14980; %e A307025 0, 8, 2664, 302844, 19005336; %e A307025 0, 12, 17556, 6530656, 1248702804, 278982789260; %e A307025 0, 18, 121838, 151793054, ...; %Y A307025 Cf. A288033 (n X n knight graph). %K A307025 nonn,tabl,more %O A307025 1,5 %A A307025 _Eric W. Weisstein_, Mar 20 2019