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

1,1

Comments

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

Links

Table of n, a(n) for n=1..25.

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A216570 A101762 A342752 * A095880 A076497 A137950

Adjacent sequences: A139452 A139453 A139454 * A139456 A139457 A139458

Keyword

nonn

Author

Artur Jasinski, Apr 21 2008

Extensions

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

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

Status

approved