A072599 Numbers n such that (n!)^2 - prime(n) is prime.

3, 4, 5, 6, 7, 16, 109, 116, 232, 877, 934

Offset: 1

Author

Rick L. Shepherd, Jun 25 2002

Keywords

• nonn
• more
• hard

Comments

Values associated with 16, 109, 116 and 232 certified prime with Primo. These primes have lengths 27, 353, 382 and 900 digits, respectively.

a(10)-a(11) associated with probable primes. - Robert Price, Aug 23 2014

a(12) > 15300. - Robert Price, Aug 23 2014

Examples

			(5!)^2 - prime(5) = 120^2 - 11 = 14400 - 11 = 14389 is prime, so 5 is a term.
		

Crossrefs

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

Programs

PARI

for(n=1,800,if(isprime((n!)^2-prime(n)),print1(n,",")))

Extensions

a(10)-a(11) from Robert Price, Aug 23 2014