|
| |
|
|
A080778
|
|
Double factorial primes; values for which n!!+1 is prime.
|
|
23
|
| |
|
|
|
OFFSET
|
1,3
|
|
|
COMMENTS
|
Numbers n such that A006882(n)+1 is prime.
|
|
|
LINKS
|
Table of n, a(n) for n=1..9.
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
|
Cf. A006882.
Sequence in context: A196290 A182446 A218436 * A007513 A283756 A071613
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
a(9) from Sou Fukui, Jan 17 2017
|
|
|
STATUS
|
approved
|
| |
|
|
