OFFSET
1,1
COMMENTS
a(24) > 50000. - Roger Karpin, Nov 13 2016
EXAMPLE
k = 6 is here because 3*6! + 1 = 2161 is prime.
PROG
(PARI) isok(n) = isprime(3*n! + 1); \\ Michel Marcus, Nov 13 2016
(PFGW) ABC2 3*$a!+1
a: from 1 to 1000 // Jinyuan Wang, Feb 05 2020
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Phillip L. Poplin (plpoplin(AT)bellsouth.net), Oct 25 2002
EXTENSIONS
More terms from Serge Batalov, Feb 18 2015
a(20)-a(23) from Roger Karpin, Nov 13 2016
STATUS
approved