A064769 Numbers n such that (n!)^2 + prime(n) is prime.

1, 2, 3, 5, 9, 17, 65, 222, 1720, 2975, 3494, 10489, 17948

Offset

1,2

Comments

Term <= 1720 certified prime with Primo.

Next term, if it exists, is greater than 2700. - Ryan Propper, Nov 05 2005

a(10)-a(13) are probable primes.

a(14) > 20000. - Robert Price, Aug 29 2014

Links

Table of n, a(n) for n=1..13.

Example

(5!)^2 + prime(5) = 120^2 + 11 = 14400 + 11 = 14411 is prime, so 5 is a term.

Prog

(PARI) for(n=1, 300, if(isprime((n!)^2+prime(n)), print1(n, ", ")))

Crossrefs

Cf. A046029, A072599 (n such that (n!)^2 - prime(n) is prime).

Sequence in context: A137155 A014227 A334816 * A320641 A365640 A047021

Adjacent sequences: A064766 A064767 A064768 * A064770 A064771 A064772

Keyword

nonn

Author

Jason Earls, Oct 18 2001

Extensions

1720 from Ryan Propper, Nov 05 2005

a(10)-a(13) from Robert Price, Aug 29 2014

Status

approved