OFFSET
0,1
COMMENTS
Since a(5) = 0, M(7) is prime.
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 mod 2^p-1. Last term: a(p-2).
EXAMPLE
a(5)= 111^2 - 2 mod 127 = 0
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
Sergio Pimentel, Apr 04 2007
STATUS
approved