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 A144273 #6 Jul 02 2023 06:07:17 %S A144273 1,1,4,19,132,1119,12057,151560,2234970,37355130,702161460, %T A144273 14608747440,333760916475,8297318063475,223043540630400, %U A144273 6444290305953675,199158606533605950,6554872218153191625,228899544451085017125,8452452568601816775000,329069272855540304587500 %N A144273 Third column (m=3) of triangle S2hat(-1) = A144270. %F A144273 a(n) = A144270(n+3,3), n>=0. %Y A144273 Cf. A144270, A144272 (column m=2). %K A144273 nonn,easy %O A144273 0,3 %A A144273 _Wolfdieter Lang_, Oct 09 2008