A139454 Numbers n such that primorial(n)/2 - 512 is prime.

5, 6, 9, 10, 11, 12, 17, 18, 23, 36, 48, 62, 87, 112, 131, 400, 1606, 6136, 6519, 11700

Offset

1,1

Comments

a(21) > 25000. - Robert Price, Jul 02 2017

Links

Table of n, a(n) for n=1..20.

Mathematica

k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 512]&&k>512, Print[n]; AppendTo[a, n]], {n, 2, 325}]; a (* corrected by Ray Chandler, Jun 16 2013 *)

Crossrefs

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

Sequence in context: A306016 A087176 A227006 * A049329 A195925 A304432

Adjacent sequences: A139451 A139452 A139453 * A139455 A139456 A139457

Keyword

nonn

Author

Artur Jasinski, Apr 21 2008

Extensions

Dropped 2 and a(16)-a(17) from Ray Chandler, Jun 16 2013

a(18)-a(20) from Robert Price, Jul 02 2017

Status

approved