A290118 Primes of the form k!/5 - 1.

23, 7983359, 95800319, 4184557977599, 74398665357980243493599889630167039999999, 6690505322632761421634012410688150333030399999999, 281001223550575979708628521248902313987276799999999, 51724648302233636128592871030722395993839526477823999999999

Offset: 1

Author

Robert Price, Jul 19 2017

Keywords

• nonn

Links

• Robert Price, Table of n, a(n) for n = 1..8
• Joe McLean, Interesting Sources of Probable Primes.
• OpenPFGW Project, Primality Tester.

Crossrefs

Cf. A139175, A139200.

Programs

Mathematica

Select[Table[k! / 5 - 1, {k, 5, 100}], PrimeQ[#]&]

Formula

a(n) = A139175(A139200(n)). - Elmo R. Oliveira, Apr 15 2025