A139455 Numbers n such that primorial(n)/2 + 1024 is prime.

3, 4, 5, 7, 11, 14, 15, 22, 30, 32, 37, 53, 83, 123, 156, 212, 215, 314, 331, 417, 555, 930, 3809, 3945, 15738

Offset: 1

Author

Artur Jasinski, Apr 21 2008

Keywords

• nonn

Comments

a(26) > 25000. - Robert Price, Jul 02 2017

Crossrefs

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

Programs

Mathematica

k = 1/2; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k + 1024], Print[n]; AppendTo[a, n]], {n, 325}]; a

PARI

isok(n) = isprime(1024+prod(k=2, n, prime(k))); \\ Michel Marcus, Jul 02 2017

Extensions

a(18)-a(22) from Ray Chandler, Jun 16 2013

a(23)-a(25) from Robert Price, Jul 02 2017