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 A139456 Numbers n such that primorial(n)/2 - 1024 is prime. 5
 5, 9, 10, 11, 16, 17, 20, 59, 96, 98, 318, 387, 938, 978, 1764, 8298, 10632, 11796, 19982 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(20) > 25000. - Robert Price, Sep 28 2017 LINKS MATHEMATICA k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 1024]&&k>1024, Print[n]; AppendTo[a, n]], {n, 2, 325}]; a CROSSREFS Cf. A067026, A067027, A139439-A139457, A103514. Sequence in context: A268412 A043682 A111102 * A195684 A135980 A314579 Adjacent sequences:  A139453 A139454 A139455 * A139457 A139458 A139459 KEYWORD nonn AUTHOR Artur Jasinski, Apr 21 2008 EXTENSIONS Drop 2,3,4 and correct program, a(12)-a(15) from Ray Chandler, Jun 16 2013 a(16)-a(19) from Robert Price, Sep 28 2017 STATUS approved

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Last modified December 13 06:15 EST 2018. Contains 318082 sequences. (Running on oeis4.)