A090472 Primes in A089897.

2, 5, 13, 103, 181, 3958349, 3745011198097903, 46240016923302054484370458782256657253421057237649913392609

Offset: 1

Author

Cino Hilliard, Feb 01 2004

Keywords

• nonn

Comments

The logarithmic integral can be computed in PARI: Li(x) = -eint1(log(1/x)).

Next term is A089897(858), which has 256 digits.

In fact the prime terms are for n=2, 3, 5, 9, 10, 26, 57, 202, 858, 1508, 1552, 2285, 4244, (5000). - Robert G. Wilson v

Crossrefs

Cf. A089897.

Programs

Mathematica

Select[ Floor[ LogIntegral[ 2^Range[202]]], PrimeQ[ # ] &] (* Robert G. Wilson v, Nov 09 2005 *)

PARI

lip(n) = forstep(x=1,n,1,y=floor(-eint1(log(1/2^x)));if(isprime(y),print1(y",")))

Extensions

Edited by David Wasserman, Nov 08 2005