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A116999
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Numbers k such that 2^k - prime(k)^2 is prime.
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0
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11, 15, 17, 23, 27, 47, 231, 457, 1249, 1529, 2343, 4693, 5939, 5997, 8367, 19855, 21295, 36583
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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15 is in the sequence because the 15th prime is 47 and 2^15 - 47^2 = 30559 is prime.
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MAPLE
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a:=proc(n) if isprime(2^n-ithprime(n)^2) then n else fi end: seq(a(n), n=1..1600); # Emeric Deutsch, Apr 06 2006
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MATHEMATICA
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PROG
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(PARI) for(i=1, 2000, if(isprime(2^i-prime(i)^2), print1(i, ", ")))
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CROSSREFS
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KEYWORD
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hard,more,nonn
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AUTHOR
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Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Apr 03 2006
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EXTENSIONS
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STATUS
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approved
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