

A080778


Double factorial primes; values for which n!!+1 is prime.


23




OFFSET

1,3


LINKS

Table of n, a(n) for n=1..8.
Ken Davis, Status of Search for Multifactorial Primes.
Ken Davis, Results for n!2+1.
Eric Weisstein's World of Mathematics, Double Factorial Prime
Eric Weisstein's World of Mathematics, Integer Sequence Primes


CROSSREFS

A006882(n)+1 is prime.
Sequence in context: A196290 A182446 A218436 * A007513 A071613 A262649
Adjacent sequences: A080775 A080776 A080777 * A080779 A080780 A080781


KEYWORD

hard,nonn


AUTHOR

Steven Harvey, Mar 11 2003


EXTENSIONS

a(7) from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
a(8) from Sou Fukui, Jun 05 2015


STATUS

approved



