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A087763
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Primes p such that 8^p - 7^p is composite.
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5
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2, 3, 5, 13, 19, 23, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 83, 89, 97, 101, 103, 107, 109, 127, 137, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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Select[Prime[Range[70]], CompositeQ[8^#-7^#]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 15 2018 *)
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PROG
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(PARI) apmb(a, b, n) = { forprime(x=2, n, y=a^x-b^x; if(!ispseudoprime(y), print1(x", "); ) ) }
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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