A139444 Numbers n such that primorial(n)/2 - 16 is prime.

4, 7, 9, 13, 22, 26, 30, 33, 36, 38, 42, 114, 125, 126, 181, 291, 296, 386, 1415, 2573, 3727, 5574, 7523, 8682, 9765

Offset: 1

Author

Artur Jasinski, Apr 21 2008

Keywords

• nonn
• more

Comments

a(26) > 25000. - Robert Price, Feb 25 2017

Crossrefs

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

Programs

Mathematica

k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 16] && k>16, Print[n]; AppendTo[a, n]], {n, 2, 752}]; a

Extensions

Drop 2 and correct program, a(16)-a(20) from Ray Chandler, Jun 16 2013

a(21)-a(25) from Robert Price, Feb 25 2017