A103539 Numbers k such that prime(k)*prime(k)# + 1 is prime where prime(k) is the k-th prime.

1, 2, 3, 4, 5, 6, 7, 11, 14, 15, 23, 27, 29, 31, 32, 34, 38, 56, 91, 231, 303, 556, 1117, 3390

Offset

1,2

Comments

Numbers k such that A000040(k)*A002110(k) + 1 is prime. - Altug Alkan, Apr 07 2016

a(25) > 8000. - Michael S. Branicky, Dec 31 2025

Links

Table of n, a(n) for n=1..24.

Example

3 is a term because 5*2*3*5 + 1 = 151 is prime.

Mathematica

Select[Range@ 600, PrimeQ[Prime@ # Product[Prime@ k, {k, #}] + 1] &] (* Michael De Vlieger, Apr 07 2016 *)

Crossrefs

Cf. A000040, A002110.

Sequence in context: A193461 A192587 A174323 * A174821 A033086 A059768

Adjacent sequences: A103536 A103537 A103538 * A103540 A103541 A103542

Keyword

nonn,more

Author

Pierre CAMI, Mar 22 2005

Extensions

a(23)-a(24) from Altug Alkan, Apr 07 2016

Status

approved