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A295111
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Primes p such that 2^p - p is also a prime.
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0
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OFFSET
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1,1
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COMMENTS
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a(6) > 1061095.
Intersection of A000040 and A048744.
Since numbers other than 3 that are congruent to 3 mod 6 are composite, for n > 2, a(n) is congruent to 1 mod 6 (see comments by Iain Fox in A048744).
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LINKS
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Table of n, a(n) for n=1..5.
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EXAMPLE
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p=13, 2^13 - 13 = 8179 is prime.
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PROG
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(PARI) lista(nn) = forprime(p=2, nn, if(ispseudoprime(2^p - p), print1(p, ", ")))
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CROSSREFS
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Cf. A000325, A081296, A048744, A057663, A057673.
Sequence in context: A234366 A084958 A249573 * A229117 A295722 A037392
Adjacent sequences: A295108 A295109 A295110 * A295112 A295113 A295114
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KEYWORD
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hard,more,nonn
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AUTHOR
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Iain Fox, Nov 14 2017
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STATUS
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approved
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