|
%I #14 Jul 19 2022 01:20:30
%S 5,11,13,17,19,23,31,37,43,47,53,59,61,71,73,79,83,89,97,101,103,107,
%T 109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,
%U 199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293
%N Primes p such that 7^p - 6^p is composite.
%t Select[Prime[Range[70]],CompositeQ[7^#-6^#]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 12 2019 *)
%o (PARI) apmb(a,b,n) = { forprime(x=2,n, y=a^x-b^x; if(!ispseudoprime(y), print1(x","); ) ) }
%Y Cf. A016169.
%Y Primes p such that k^p - (k-1)^p is composite: A087489 (k=3), A087490 (k=4), A087685 (k=5), A087749 (k=6), this sequence (k=7), A087763 (k=8), A087894 (k=9), A087895 (k=10).
%K nonn
%O 1,1
%A _Cino Hilliard_, Oct 26 2003
%E Offset corrected by _Mohammed Yaseen_, Jul 18 2022
|
