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 A027257 #9 Oct 27 2019 11:35:35 %S A027257 1,2,8,58,462,3782,31436,264134,2237640,19079574,163538472,1407813438, %T A027257 12163015662,105407889930,915913267652,7976914859210,69613332125342, %U A027257 608590829593638,5329041851925256,46729591602635246,410291878420535354,3606612469259086834 %N A027257 a(n) = self-convolution of row n of array T given by A025177. %Y A027257 Cf. A025177. %K A027257 nonn %O A027257 0,2 %A A027257 _Clark Kimberling_ %E A027257 a(1) corrected and more terms from _Sean A. Irvine_, Oct 26 2019