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 A299503 #11 Feb 26 2018 12:15:43
%S A299503 42,23940,12795048,6852216840,3669291602172,1964875343509008,
%T A299503 1052174343447263568,563430581238674063376,301712374716950167413282,
%U A299503 161564459029576395778765080,86516419639708839110100858360,46328820782943003562067180265504
%N A299503 a(n) = (1/12) * Sum_{d|n} d * A288851(d).
%Y A299503 Cf. A013973 (E_6), A109817, A288851, A289540, A300025.
%K A299503 nonn
%O A299503 1,1
%A A299503 _Seiichi Manyama_, Feb 26 2018