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 A300147 #12 Jun 07 2018 03:53:30
%S A300147 -30,6660,-1536120,354476040,-81800478900,18876653594640,
%T A300147 -4356063194112240,1005225129672310800,-231970363216834560390,
%U A300147 53530545369975222475800,-12352954264801690636800360,2850624405442199478575792160
%N A300147 a(n) = (1/8) * Sum_{d|n} d * A110163(d).
%H A300147 Vaclav Kotesovec, <a href="/A300147/b300147.txt">Table of n, a(n) for n = 1..420</a>
%F A300147 a(n) ~ (-1)^n * exp(Pi*sqrt(3)*n) / 8. - _Vaclav Kotesovec_, Jun 07 2018
%Y A300147 Cf. A004009 (E_4), A108091, A110163, A289247, A300025.
%K A300147 sign
%O A300147 1,1
%A A300147 _Seiichi Manyama_, Feb 26 2018