1,3

Conjecture: 77! + 1 is the largest factorial Chen prime.

For n>2, n is in the sequence iff both numbers n!/3+1 and n!+1 are primes. - Farideh Firoozbakht (mymontain(AT)yahoo.com), Mar 24 2006

Cf. A002981, A109611.

Adjacent sequences: A109129 A109130 A109131 this_sequence A109133 A109134 A109135

Sequence in context: A066046 A065597 A001052 this_sequence A008510 A042165 A089921

hard,more,nonn

Jason Earls (zevi_35711(AT)yahoo.com), Aug 17 2005