OFFSET
0,1
COMMENTS
Since a(9) > 0, M(11) is composite. In fact, 2047 = 23 * 89
LINKS
Eric Weisstein's World of Mathematics, Lucas Lehmer Test.
Wikipedia, Lucas Lehmer Primality Test.
FORMULA
a(0) = 4; a(n) = a(n-1)^2-2 mod 2^p-1. Last term: a(p-2).
EXAMPLE
a(9) = a(8)^2 - 2 mod 2047 = 282^2 - 2 mod 2047 = 1736.
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
Sergio Pimentel, Apr 05 2007
EXTENSIONS
Offset corrected by Nathaniel Johnston, May 31 2011
STATUS
approved