A139453 Numbers n such that primorial(n)/2 + 512 is prime.

4, 5, 6, 7, 9, 12, 73, 129, 142, 144, 253, 455, 531, 734, 1009, 1193, 1553, 2449, 3309, 13534, 17513, 17832, 22852

Offset: 1

Author

Artur Jasinski, Apr 21 2008

Keywords

• nonn

Comments

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

Crossrefs

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

Programs

Mathematica

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

Extensions

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

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