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 A055301 #8 Apr 20 2023 18:22:34 %S A055301 1,-1,0,1,0,-3,-1,14,20,-77,-308,147,3965,12527,-26255,-446923, %T A055301 -1127033,9020388,71170748,57286010,-2168151928,-17700260071, %U A055301 -11899834419,993097077555,7077421523510,-12873010724109 %N A055301 Column 2 of triangle A055300. %H A055301 <a href="/index/Tra#trees">Index entries for sequences related to trees</a> %Y A055301 Cf. A055300. %K A055301 sign %O A055301 2,6 %A A055301 _Christian G. Bower_, May 09 2000