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Primes in A047783.
1

%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