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Primes p such that 9^p - 8^p is composite.
5

%I #15 Jul 19 2022 01:33:48

%S 3,5,11,13,17,19,23,37,41,43,47,53,59,61,71,73,79,83,89,97,101,103,

%T 107,109,113,127,131,137,139,151,157,163,167,173,179,181,191,193,197,

%U 199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307

%N Primes p such that 9^p - 8^p is composite.

%t Select[Prime[Range[100]],!PrimeQ[9^#-8^#]&] (* _Harvey P. Dale_, May 01 2011 *)

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

%Y Cf. A016185.

%Y Primes p such that k^p - (k-1)^p is composite: A087489 (k=3), A087490 (k=4), A087685 (k=5), A087749 (k=6), A087759 (k=7), A087763 (k=8), this sequence (k=9), A087895 (k=10).

%K nonn

%O 1,1

%A _Cino Hilliard_, Oct 26 2003

%E Offset corrected by _Mohammed Yaseen_, Jul 19 2022