A087685 - OEIS

%I #10 Feb 16 2021 01:00:18

%S 2,5,7,11,13,17,19,23,29,31,37,41,47,53,61,67,71,73,79,83,89,97,101,

%T 103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,193,

%U 197,199,211,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307

%N Primes p such that 5^p - 4^p is composite.

%o (PARI) apmb(a,b,n) = { forprime(x=2,n, y=a^x-b^x; if(!ispseudoprime(y), print1(x","); ) ) }

%Y Cf. A005060.

%K nonn

%O 1,1

%A _Cino Hilliard_, Oct 26 2003

%E Checked by _Ray Chandler_, Apr 24 2007