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 A176656 #5 Feb 19 2017 09:23:29 %S A176656 1,9,12,15,16,19,22,23,24,25,30,31,32,37,38,39,40,47,48,51,54,55,56, %T A176656 59,62,63,66,67,68,71,72,73,74,75,76,77,78,79,80,85,86,87,88,91,92,93, %U A176656 94,95,96,97,100,101,102,103,106,107,108,111,112,115,118,119,122,123,124 %N A176656 The positions of single (or isolated or non-twin) primes in A000040. %F A176656 A000040(a(n))=A007510(k). %p A176656 A176656 := proc(n) numtheory[pi](A007510(n)) ; end proc: seq(A176656(n),n=1..120) ; # _R. J. Mathar_, Apr 26 2010 %K A176656 nonn %O A176656 1,2 %A A176656 _Juri-Stepan Gerasimov_, Apr 23 2010 %E A176656 Corrected (32 inserted, one of the 94 removed, 103 inserted, 121 replaced by 122) by _R. J. Mathar_, Apr 26 2010