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Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
13 is there because it is prime and 4*13 = 23+29.
If[PrimeQ[P = (Prime[k] + Prime[k + 1])/4], Print[P]]
(PARI) is(n)=isprime(n) && precprime(2*n)+nextprime(2*n)==4*n \\ Charles R Greathouse IV, Apr 24 2015
Sequence in context: A215359 A115898 A215350 * A215386 A143871 A225517
Adjacent sequences: A118131 A118132 A118133 * A118135 A118136 A118137
Anton Vrba (antonvrba(AT)yahoo.com), May 13 2006
Edited by Don Reble (djr(AT)nk.ca), Jul 23 2006