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

%I #13 Jul 04 2024 16:18:31

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

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

%C a(16) > 12000. - _Michael S. Branicky_, Jul 04 2024

%H <a href="/index/Pri#primepop">Index entries for sequences related to numbers of primes of the form k*n!+-1</a>

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

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

%K nonn,more

%O 1,1

%A _Robert G. Wilson v_, Sep 13 2010

%E a(12)-a(14) from _Jinyuan Wang_, Feb 04 2020

%E a(15) from _Michael S. Branicky_, Jul 03 2024