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 A174009 #7 Apr 16 2014 00:46:37 %S A174009 1,4,5,11,13,16,18,19,20,25,33,37,38,39,40,48,52,59,60,69,72,73,76,79, %T A174009 84,85,86,87,96,98,104,110,117,122,135,136,140,142,145,151,153,160, %U A174009 162,173,179,183,186,191,192,199,200,206,214,218,221,226,232,234,239,242 %N A174009 Numbers n such that A174008(k)=n-th prime. %C A174009 n-th prime in sequence A174008. %e A174009 a(1)=1 because A174008(1)=2=1st prime; %e A174009 a(2)=4 because A174008(2)=7=4th prime; %e A174009 a(3)=5 because A174008(3)=11=5th prime; %e A174009 a(4)=11 because A174008(7)=31=11th prime. %p A174009 From _R. J. Mathar_, Apr 28 2010: (Start) %p A174009 A163300 := proc(n) option remember ; if n = 1 then 0; else for a from procname(n-1)+2 by 2 do if not isprime(a) then return a ; end if; end do; end if; end proc: %p A174009 A174008 := proc(n) ithprime(n)+A163300(n) ; end proc: %p A174009 A174009 := proc(k) p := A174008(k) ; if isprime(p) then printf("%d,", numtheory[pi](p) ) ; end if; return ; end proc: %p A174009 seq(A174009(k),k=1..400 ) ; (End) %Y A174009 Cf. A000040, A001477, A078916, A163300, A174008. %K A174009 nonn %O A174009 1,2 %A A174009 _Juri-Stepan Gerasimov_, Mar 05 2010 %E A174009 More terms from _R. J. Mathar_, Apr 28 2010