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 A090472 #8 Mar 20 2015 23:30:00 %S A090472 2,5,13,103,181,3958349,3745011198097903, %T A090472 46240016923302054484370458782256657253421057237649913392609 %N A090472 Primes in A089897. %C A090472 The logarithmic integral can be computed in PARI: Li(x) = -eint1(log(1/x)). %C A090472 Next term is A089897(858), which has 256 digits. %C A090472 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_ %t A090472 Select[ Floor[ LogIntegral[ 2^Range[202]]], PrimeQ[ # ] &] (* _Robert G. Wilson v_, Nov 09 2005 *) %o A090472 (PARI) lip(n) = forstep(x=1,n,1,y=floor(-eint1(log(1/2^x)));if(isprime(y),print1(y","))) %Y A090472 Cf. A089897. %K A090472 nonn %O A090472 1,1 %A A090472 _Cino Hilliard_, Feb 01 2004 %E A090472 Edited by _David Wasserman_, Nov 08 2005