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 A214337 #14 Jan 08 2024 09:38:59 %S A214337 0,0,41,0,690,16925,0,7150,237652,4306778,0,58760,2518957,56864524, %T A214337 910734615,0,420182,22417804,613687758,11675167470,174833737848 %N A214337 Triangle read by rows: T(n,k) = number of rooted maps with n vertices and k faces on a non-orientable surface of type 3/2 (0 <= k <= n). %H A214337 Didier Arquès and Alain Giorgetti, <a href="https://doi.org/10.1016/S0304-3975(98)00230-8">Counting rooted maps on a surface</a>, Theoret. Comput. Sci. 234 (2000), no. 1-2, 255--272. MR1745078 (2001f:05078). %e A214337 Triangle begins: %e A214337 0; %e A214337 0, 41; %e A214337 0, 690, 16925; %e A214337 0, 7150, 237652, 4306778; %e A214337 0, 58760, 2518957, 56864524, 910734615; %e A214337 0, 420182, 22417804, 613687758, 11675167470, 174833737848; %e A214337 ... %Y A214337 Diagonals give A118448, A214335, A213336, A213338. %Y A214337 Cf. A214806. %K A214337 nonn,tabl %O A214337 0,3 %A A214337 _N. J. A. Sloane_, Jul 27 2012