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

1,1

Comments

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

Links

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

Mathematica

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

Crossrefs

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

Sequence in context: A310963 A082869 A320691 * A353020 A166569 A024608

Adjacent sequences: A139441 A139442 A139443 * A139445 A139446 A139447

Keyword

nonn,more

Author

Artur Jasinski, Apr 21 2008

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

Status

approved