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

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

Offset

1,1

Comments

a(15) > 5174. - Jinyuan Wang, Feb 04 2020

Links

Table of n, a(n) for n=1..14.

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

Mathematica

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

Crossrefs

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

Sequence in context: A028354 A028355 A074920 * A102842 A299169 A009263

Adjacent sequences: A180628 A180629 A180630 * A180632 A180633 A180634

Keyword

nonn,more

Author

Robert G. Wilson v, Sep 13 2010

Extensions

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

Status

approved