A129219 Residues of the Lucas - Lehmer primality test for M(7) = 127.

4, 14, 67, 42, 111, 0

Offset

0,1

Comments

Since a(5) = 0, M(7) is prime.

Links

Table of n, a(n) for n=0..5.

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

Cf. A095847, A003010, A129220, A129221, A129222, A129223, A129224, A129225, A129226.

Sequence in context: A126787 A187742 A347432 * A292719 A292720 A292721

Adjacent sequences: A129216 A129217 A129218 * A129220 A129221 A129222

Keyword

fini,full,nonn

Author

Sergio Pimentel, Apr 04 2007

Status

approved