A364698 Numbers k such that k! + k^2 + k - 1 is prime.

1, 2, 3, 4, 5, 6, 9, 11, 13, 1045

Offset: 1

Author

Saish S. Kambali, Aug 03 2023

Keywords

• nonn
• more

Comments

a(11) > 10^4, if it exists. - Amiram Eldar, Aug 05 2023

a(11) > 2*10^4, if it exists. - Michael S. Branicky, Jul 05 2024

Examples

			For k = 2, 2! + 2^2 + 2 - 1 = 7 is a prime.
		

Crossrefs

Cf. A066143, A079649.

Programs

Mathematica

Select[Range[1100], PrimeQ[#! + #^2 + # - 1] &] (* Amiram Eldar, Aug 03 2023 *)

PARI

for (k=1,10^3,if(ispseudoprime(k! + k^2 + k - 1),print1(k,", ")))

Extensions

a(10) from Amiram Eldar, Aug 03 2023