A118222 Numbers k such that k! * prime(k)# + 1 is prime.

0, 1, 2, 3, 48, 151, 312, 445, 4343, 6765

Offset

1,3

Comments

a(2)-a(8) found and primes proved by PrimeForm ([N-1, Brillhart-Lehmer-Selfridge]).

Links

Table of n, a(n) for n=1..10.

Example

3 is a term as 3! * prime(3)# + 1 = 3*2*1 * 5*3*2 + 1 = 181, a prime.

Crossrefs

Cf. A002110, A118223.

Sequence in context: A163488 A215536 A173355 * A191594 A208204 A067092

Adjacent sequences: A118219 A118220 A118221 * A118223 A118224 A118225

Keyword

nonn,more

Author

Rick L. Shepherd, Apr 15 2006

Extensions

a(9) from Michael S. Branicky, Dec 13 2023

a(1)=0 inserted and a(10) from Michael S. Branicky, Sep 09 2024

Status

approved