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 A294261 #14 Oct 27 2017 09:57:50
%S A294261 1,-1,1,-7,49,-301,2281,-21211,260737,-3254329,41086801,-589336111,
%T A294261 9851907121,-170708882917,3060177746809,-60544788499651,
%U A294261 1298663388032641,-28777111728560881,665551703689032097,-16413980708818538839,428253175770218766001
%N A294261 E.g.f.: exp(Sum_{n>=1} A081362(n)*x^n).
%H A294261 Seiichi Manyama, <a href="/A294261/b294261.txt">Table of n, a(n) for n = 0..437</a>
%F A294261 a(0) = 1 and a(n) = (n-1)! * Sum_{k=1..n} k*A081362(k)*a(n-k)/(n-k)! for n > 0.
%Y A294261 Main diagonal of A294289.
%Y A294261 Cf. A058892, A293840.
%K A294261 sign
%O A294261 0,4
%A A294261 _Seiichi Manyama_, Oct 26 2017