1,1

Table of n, a(n) for n=1..20.

C. Pomerance, Science News reference.

For x = 2 abs(7^2-2^11) = 1999 which is prime. So 2 is the first entry.

(PARI) g(n) = for(x=1, n, y=abs(7^x-2^11); if(ispseudoprime(y), print1(x", ")))

Sequence in context: A003306 A250305 A136585 * A014224 A175342 A077312

Adjacent sequences: A122718 A122719 A122720 * A122722 A122723 A122724

easy,nonn

Cino Hilliard, Sep 23 2006

approved