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 A107827 #2 Mar 30 2012 17:26:16 %S A107827 7,4,12,2,6,5,8,10,1,9,11,13,14,15,19,18,20,21,16,3,17,22,24,23,27,26, %T A107827 28,25,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49, %U A107827 50,51,52,53,54,55,56,57,58,59,60,61 %N A107827 Indices of primes occurring in A107807. %F A107827 A107827(n)=pi(A107807(n)) %Y A107827 Cf. A107801 - A107814, A107821, A107822, A107823, A107824, A107825, A107826, A107828, A107829, A107830, A107831, A107832, A107833, A107834. %K A107827 easy,nonn %O A107827 1,1 %A A107827 _Zak Seidov_, May 24 2005