A129220 Residues of the Lucas - Lehmer primality test for M(11) = 2047.

4, 14, 194, 788, 701, 119, 1877, 240, 282, 1736

Offset

0,1

Comments

Since a(9) > 0, M(11) is composite. In fact, 2047 = 23 * 89

Links

Table of n, a(n) for n=0..9.

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

Cf. A095847, A003010, A129218, A129219, A129221, A129222, A129223, A129224, A129225, A129226, A001348.

Sequence in context: A098851 A080986 A132555 * A129221 A129222 A129223

Adjacent sequences: A129217 A129218 A129219 * A129221 A129222 A129223

Keyword

fini,full,nonn

Author

Sergio Pimentel, Apr 05 2007

Extensions

Offset corrected by Nathaniel Johnston, May 31 2011

Status

approved