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A109132
Numbers n such that n! + 1 is a Chen prime. n! + 1 is then called a factorial Chen prime.
0
0, 1, 2, 3, 11, 77
OFFSET
1,3
COMMENTS
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, Mar 24 2006
CROSSREFS
Sequence in context: A349518 A155187 A338613 * A279084 A008510 A290512
KEYWORD
hard,more,nonn
AUTHOR
Jason Earls, Aug 17 2005
STATUS
approved