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A139453 Numbers n such that primorial(n)/2 + 512 is prime. 5
4, 5, 6, 7, 9, 12, 73, 129, 142, 144, 253, 455, 531, 734, 1009, 1193, 1553, 2449, 3309, 13534, 17513, 17832, 22852 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(24) > 25000. - Robert Price, May 22 2017

LINKS

Table of n, a(n) for n=1..23.

MATHEMATICA

k = 1/2; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k + 512], Print[n]; AppendTo[a, n]], {n, 325}]; a

CROSSREFS

Cf. A067026, A067027, A139439-A139457, A103514.

Sequence in context: A215046 A008523 A047568 * A010391 A010419 A255137

Adjacent sequences:  A139450 A139451 A139452 * A139454 A139455 A139456

KEYWORD

nonn

AUTHOR

Artur Jasinski, Apr 21 2008

EXTENSIONS

a(12)-a(18) from Ray Chandler, Jun 16 2013

a(19)-a(23) from Robert Price, May 22 2017

STATUS

approved

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Last modified April 25 23:48 EDT 2019. Contains 322465 sequences. (Running on oeis4.)