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A129219
Residues of the Lucas - Lehmer primality test for M(7) = 127.
8
4, 14, 67, 42, 111, 0
OFFSET
0,1
COMMENTS
Since a(5) = 0, M(7) is prime.
LINKS
Eric Weisstein's World of Mathematics, Lucas Lehmer 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
KEYWORD
fini,full,nonn
AUTHOR
Sergio Pimentel, Apr 04 2007
STATUS
approved