%I #5 Oct 01 2013 17:57:56
%S 2,2,3,5,5,7,7,7,11,11,11,13,13,13,13,17,17,17,17,19,19,19,19,23,23,
%T 23,23,29,29,29,29,29,31,31,31,31,37,37,37,37,37,41,41,41,41,41,43,43,
%U 43,43,43,47,47,47,47,47,53,53,53,53,53,53,59,59,59,59,59,59,61,61,61,61
%N Primes in A047783.
%C The logarithmic integral can be computed in PARI: Li(x) = -eint1(log(1/x)).
%o (PARI) lip(n) = forstep(x=1,n,1,y=floor(-eint1(log(1/x)));if(isprime(y),print1(y",")))
%Y Cf. A047783.
%K easy,nonn
%O 1,1
%A _Cino Hilliard_, Feb 01 2004
%E Edited by _David Wasserman_, Nov 16 2005