

A081712


n!  n# + 1 is prime, where n# is the primorial function.


3



4, 6, 7, 8, 10, 20, 21, 26, 101, 119, 172, 409, 621, 1043, 1204, 1283, 1673, 2003, 4336, 5773, 12913, 13517
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,1


COMMENTS

Some of the larger entries may only correspond to probable primes.


LINKS

Table of n, a(n) for n=0..21.
Mike Oakes, Primofactorials.
Mike Oakes, Primofactorials, message 12028 in primenumbers Yahoo group, Apr 3, 2003. [Cached copy]
Joe McLean, Interesting Sources of Probable Primes.


EXAMPLE

a(1)=4 because 4!4#+1=19 is prime


CROSSREFS

Cf. A081710, A081711, A081713.
Sequence in context: A284623 A139490 A030375 * A178663 A084395 A047291
Adjacent sequences: A081709 A081710 A081711 * A081713 A081714 A081715


KEYWORD

nonn,more,hard


AUTHOR

Mike Oakes, Apr 04 2003


EXTENSIONS

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


STATUS

approved



