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%I #15 Feb 05 2020 08:18:23
%S 2,3,4,6,7,9,10,13,23,25,32,38,40,47,96,3442,4048,4522,4887,7033,9528,
%T 12915,31762
%N Numbers k such that 3*k! + 1 is prime.
%C a(24) > 50000. - _Roger Karpin_, Nov 13 2016
%e k = 6 is here because 3*6! + 1 = 2161 is prime.
%o (PARI) isok(n) = isprime(3*n! + 1); \\ _Michel Marcus_, Nov 13 2016
%o (PFGW) ABC2 3*$a!+1
%o a: from 1 to 1000 // _Jinyuan Wang_, Feb 05 2020
%Y Cf. A002981, A051915, A076680, A076681, A076682, A076683, A178488, A180626, A126896.
%K nonn,more
%O 1,1
%A Phillip L. Poplin (plpoplin(AT)bellsouth.net), Oct 25 2002
%E More terms from _Serge Batalov_, Feb 18 2015
%E a(20)-a(23) from _Roger Karpin_, Nov 13 2016
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