1,3

1976!+1976!!+1 is a 5657-digits prime. Next term is greater than 4000.

Joe McLean, Interesting Sources of Probable Primes

6!+6!!+1=769, which is prime.

Cf. A000142, A001147, A116897.

Sequence in context: A161632 A115974 A066864 this_sequence A061062 A152479 A115961

Adjacent sequences: A116893 A116894 A116895 this_sequence A116897 A116898 A116899

hard,more,nonn

Giovanni Resta (g.resta(AT)iit.cnr.it), Mar 04 2006

5126 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008