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 A177951 #4 Mar 30 2012 18:35:53 %S A177951 4,1,3,2,8,7,7,4,4,9,3,6,6,29,10,5,5,5,8,8,8,8,28,28,7,7,7,7,30,30,30, %T A177951 4,13,13,27,27,9,9,9,9,9,9,9,19,11,11,11,11,11,11,6,6,6,6,26,26,6,6, %U A177951 31,23,31,15,15,29,15,29,29,29,15,15,10,10,10,10,10,10,10,10,10,21,12,12,12 %N A177951 PrimePi(A066903(n)), the index of A066903(n) in the primes. %F A177951 a(n) = A000720(A066903(n)) = A049084(A066903(n)) . [R. J. Mathar, May 28 2010] %e A177951 a(14)= 29 because prime(29) = 109, and A066903(14) = 109. %Y A177951 Cf. A006577, A066903. %K A177951 nonn %O A177951 1,1 %A A177951 _Michel Lagneau_, May 15 2010 %E A177951 Clearer definition from _R. J. Mathar_, May 28 2010