|
Search: id:A082671
|
|
|
| A082671 |
|
Numbers n such that (n!-2)/2 is a prime or pseudo prime. |
|
+0
2
|
|
| 3, 4, 5, 6, 9, 31, 41, 373, 589, 812, 989, 1115, 1488, 1864, 1918, 4412, 4686, 5821, 13830
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
(4!-2)/2 = 11 is a prime
|
|
PROGRAM
|
(PARI) \ x such that (x!-2)/2 is prime xfactpk(n, -2) = { for(x=2, n, y = (x!+k)/k; if(isprime(y), print1(x" ")) ) }
|
|
CROSSREFS
|
Adjacent sequences: A082668 A082669 A082670 this_sequence A082672 A082673 A082674
Sequence in context: A014101 A039035 A065798 this_sequence A059877 A047307 A138918
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Cino Hilliard (hillcino368(AT)gmail.com), May 18 2003
|
|
EXTENSIONS
|
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
|
|
|
Search completed in 0.002 seconds
|
