A290121 Primes of the form k!/8 - 1.

2, 89, 5039, 453599, 4989599, 2615348735999, 15205637551103999, 32327905188896022580370544394201497496149704048639999999999, 68043117384680383000466155030980344080536633048599859316607515858708885143551999999999999999

Offset: 1

Author

Robert Price, Jul 19 2017

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..9
• Joe McLean, Interesting Sources of Probable Primes.
• OpenPFGW Project, Primality Tester.

Crossrefs

Cf. A139183, A139203.

Programs

Mathematica

Select[Table[k! / 8 - 1, {k, 4, 100}], PrimeQ[#]&]

Formula

a(n) = A139183(A139203(n)). - Elmo R. Oliveira, Apr 16 2025

Extensions

Missing terms inserted by Alois P. Heinz, Dec 05 2024