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A172071
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Primes p such that either p - 5/2 -+ 7/2 is prime.
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2
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2, 11, 13, 17, 19, 23, 29, 37, 43, 47, 53, 59, 67, 73, 79, 89, 103, 107, 109, 113, 137, 157, 163, 173, 179, 197, 199, 229, 233, 239, 257, 263, 269, 277, 283, 313, 317, 337, 353, 359, 373, 379, 389, 439, 449, 463, 467, 509, 547, 563, 569, 577, 593, 599, 607, 613
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OFFSET
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1,1
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COMMENTS
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Two together with values of p+6 where (p,p+6) are both prime.
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LINKS
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EXAMPLE
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2 is a term because 2 - 5/2 - 7/2 = -4 (nonprime) and 2 - 5/2 + 7/2 = 3 (prime).
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MAPLE
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for n from 1 to 200 do p := ithprime(n) ; if isprime(p+1) <> isprime(p-6) then printf("%d, ", p) ; end if; end do: # R. J. Mathar, Apr 24 2010
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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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