



49, 61, 64, 74, 95, 104, 110, 125, 146, 151, 154, 163, 166, 173, 184, 199, 205, 209, 215, 229, 238, 244, 250, 259, 266, 269, 278, 293, 314, 320, 335, 346, 350, 355, 359, 364, 376, 385, 391, 394, 398, 403, 410, 419, 424, 427, 436, 439, 448, 451, 454, 460
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OFFSET

1,1


COMMENTS

Usually the greatest p with p,q both prime, p+q = 2m, is equal to the largest prime <= 2m2, but not always. These are the exceptions.
Almost all natural numbers are in the sequence so the above comment is misleading in general, and only fitting for small numbers.  Jens Kruse Andersen, Jul 13 2014


LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000


MATHEMATICA

a2[n_] := {p, q} /. {ToRules @ Reduce[p+q == 2*n, {p, q}, Primes]} // Max; a8[n_] := Max[FactorInteger[(2*n)!/n!^2]]; Select[Range[500], a2[#] != a8[#1]&] (* JeanFrançois Alcover, Dec 19 2013 *)


PROG

(PARI) for(m=2, 1000, p=precprime(2*m2); if(!isprime(2*mp), print1(m", "))) \\ Jens Kruse Andersen, Jul 12 2014


CROSSREFS

Cf. A020482, A060308.
Sequence in context: A304950 A316618 A039472 * A111327 A184033 A178951
Adjacent sequences: A135142 A135143 A135144 * A135146 A135147 A135148


KEYWORD

nonn


AUTHOR

Harry J. Smith, Nov 20 2007


STATUS

approved



