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 A351110 #11 Feb 18 2023 08:07:37 %S A351110 1,1,0,1,1,6,1,0,15,2,1,1,70,289,9436,1,0,294,191,128020 %N A351110 Triangle read by rows: T(m,n) is the number of paths for a Racetrack car (using Moore neighborhood) with initial velocity zero, going from one corner to the diagonally opposite corner on an m X n grid, such that all positions are visited exactly once, 1 <= n <= m. %C A351110 For a Racetrack car using von Neumann neighborhood (see A351042), there are no such paths if 2 <= n <= m, because the car will never be able to leave a corner of the grid (except the corner where it starts). %H A351110 Wikipedia, <a href="https://en.wikipedia.org/wiki/Racetrack_(game)">Racetrack</a> %e A351110 Triangle begins: %e A351110 m\n| 1 2 3 4 5 6 %e A351110 ---+----------------------- %e A351110 1 | 1 %e A351110 2 | 1 0 %e A351110 3 | 1 1 6 %e A351110 4 | 1 0 15 2 %e A351110 5 | 1 1 70 289 9436 %e A351110 6 | 1 0 294 191 128020 ? %Y A351110 Cf. A000012 (column n=1), A000035 (column n=2), A272445, A351041, A351042, A351106, A351111 (main diagonal). %K A351110 nonn,tabl,more %O A351110 1,6 %A A351110 _Pontus von Brömssen_, Feb 01 2022