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A180631 Numbers k such that 10*k! - 1 is prime. 10
2, 3, 4, 33, 55, 95, 110, 148, 170, 612, 1155, 2295, 2473, 4143 (list; graph; refs; listen; history; text; internal format)
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

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Last modified April 13 17:30 EDT 2021. Contains 342936 sequences. (Running on oeis4.)