A180631 Numbers k such that 10*k! - 1 is prime.

2, 3, 4, 33, 55, 95, 110, 148, 170, 612, 1155, 2295, 2473, 4143, 5671

Offset: 1

Author

Robert G. Wilson v, Sep 13 2010

Keywords

• nonn
• more

Comments

a(16) > 12000. - Michael S. Branicky, Jul 04 2024

Links

• Index entries for sequences related to numbers of primes of the form k*n!+-1

Crossrefs

Cf. A002982, A076133, A076134, A099350, A099351, A180627, A180628, A180630, A180630.

Programs

Mathematica

fQ[n_] := PrimeQ[10 n! - 1]; k = 0; lst = {}; While[k < 1501, If[ fQ@k, AppendTo[lst, k]; Print@k]; k++ ]; lst

Extensions

a(12)-a(14) from Jinyuan Wang, Feb 04 2020

a(15) from Michael S. Branicky, Jul 03 2024