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 A342936 #21 Apr 11 2021 22:16:23 %S A342936 1,1,1,1,0,1,1,2,2,1,1,0,4,0,1,1,4,6,6,4,1,1,0,13,0,13,0,1,1,8,20,34, %T A342936 34,20,8,1,1,0,43,0,120,0,43,0,1,1,16,66,187,320,320,187,66,16,1,1,0, %U A342936 142,0,1137,0,1137,0,142,0,1,1,32,218,1026,3026,5321,5321,3026,1026,218,32,1 %N A342936 Array T(n, k), n, k > 0, read by antidiagonals; T(n, k) is the number of rotationally symmetric self-avoiding rook paths joining opposite corners of an n X k board. %H A342936 Rémy Sigrist, <a href="/A342936/a342936.png">Illustration of T(5, 6) = 320</a> %H A342936 Rémy Sigrist, <a href="/A342936/a342936.txt">C program for A342936</a> %H A342936 <a href="/index/Wa#WALKS">Index entries for sequences related to walks</a> %F A342936 T(n, k) <= A064298(n, k). %F A342936 T(n, k) = T(k, n). %F A342936 T(n, k) = 0 iff n and k are both even. %F A342936 T(n, 1) = 1. %F A342936 T(2*k+1, 2) = 2^k for any k >= 0. %e A342936 Array T(n, k) begins: %e A342936 n\k| 1 2 3 4 5 6 7 8 9 %e A342936 ---+----------------------------------------------------------- %e A342936 1| 1 1 1 1 1 1 1 1 1 %e A342936 2| 1 0 2 0 4 0 8 0 16 %e A342936 3| 1 2 4 6 13 20 43 66 142 %e A342936 4| 1 0 6 0 34 0 187 0 1026 %e A342936 5| 1 4 13 34 120 320 1137 3026 10725 %e A342936 6| 1 0 20 0 320 0 5321 0 87298 %e A342936 7| 1 8 43 187 1137 5321 32916 152606 939548 %e A342936 8| 1 0 66 0 3026 0 152606 0 7592509 %e A342936 9| 1 16 142 1026 10725 87298 939548 7592509 81253506 %o A342936 (C) See Links section. %Y A342936 Cf. A064298. %K A342936 nonn,tabl,walk %O A342936 0,8 %A A342936 _Rémy Sigrist_, Apr 11 2021