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 A294291 #9 Oct 27 2017 10:14:18
%S A294291 1,-1,1,-7,73,-421,2641,-32131,403537,-4527433,57723841,-902025631,
%T A294291 15198774361,-258241785517,4617616213393,-92675891536411,
%U A294291 2008139896617121,-44077045165245841,1009237851013130497,-25134834585692446903,658430145120963410281
%N A294291 E.g.f.: exp(1/((1+x)*(1+x^2)*(1+x^3)) - 1).
%H A294291 Seiichi Manyama, <a href="/A294291/b294291.txt">Table of n, a(n) for n = 0..440</a>
%o A294291 (PARI) N=66; x='x+O('x^N); Vec(serlaplace(exp(1/((1+x)*(1+x^2)*(1+x^3))-1)))
%Y A294291 Column k=3 of A294289.
%K A294291 sign
%O A294291 0,4
%A A294291 _Seiichi Manyama_, Oct 27 2017