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A057181
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Numbers n such that (15^n + 1)/16 is a prime.
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16
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OFFSET
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1,1
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COMMENTS
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a(6), a(7) and a(8) correspond to probable primes.
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LINKS
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J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.
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MATHEMATICA
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PROG
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(Prime95) PRP=1, 15, 551927, 1, 0, 0, "16"
(PARI) isok(n) = (denominator(p=(15^n+1)/16)==1) && isprime(p); \\ Michel Marcus, Oct 29 2017
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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