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 A027566 #4 Mar 31 2012 12:34:58 %S A027566 1,18,126,1652 %N A027566 Number of numbers not of form k_1 k_2 .. k_n (1/k_1 + .. + 1/k_n), k_i >= 1. %Y A027566 Cf. A025052, A027563, A027565, A027565. %K A027566 nonn,hard,nice %O A027566 2,2 %A A027566 _R. H. Hardin_