

A139452


Numbers n such that primorial(n)/2  256 is prime.


5



6, 8, 16, 27, 66, 74, 168, 253, 458, 1310, 2665, 2681, 2718, 2836, 4921, 7356, 11466
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OFFSET

1,1


COMMENTS

a(18) > 25000.  Robert Price, May 22 2017


LINKS

Table of n, a(n) for n=1..17.


MATHEMATICA

k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k  256]&&k>256, Print[n]; AppendTo[a, n]], {n, 2, 325}]; a


CROSSREFS

Cf. A067026, A067027, A139439A139457, A103514.
Sequence in context: A006583 A011989 A270821 * A245643 A299030 A127400
Adjacent sequences: A139449 A139450 A139451 * A139453 A139454 A139455


KEYWORD

nonn


AUTHOR

Artur Jasinski, Apr 21 2008


EXTENSIONS

Drop 3,4 and correct program, a(9)a(14) from Ray Chandler, Jun 16 2013
a(15)a(17) from Robert Price, May 22 2017


STATUS

approved



