A358805 Numbers k such that k! + (k!/2) + 1 is prime.

4, 5, 7, 11, 12, 14, 18, 28, 30, 62, 135, 153, 275, 584, 630, 1424, 1493, 4419, 8492, 10950

Offset: 1

Author

Arsen Vardanyan, Dec 01 2022

Keywords

• nonn
• more

Comments

Numbers k such that A070960(k)+1 is prime.

No more terms < 10000. - Vaclav Kotesovec, Dec 12 2022

Links

• Table of n, a(n) for n = 1..19
• Arsen Vardanyan, A list of prime numbers

Crossrefs

Cf. A070960, A358878.

Programs

PARI

is(k) = isprime(k!+(k!/2)+1);

Extensions

a(18)-a(19) from Vaclav Kotesovec, Dec 09 2022

a(20) from Michael S. Branicky, Aug 02 2024