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A129224 Residues of the Lucas - Lehmer primality test for M(23) = 8388607. 7
4, 14, 194, 37634, 7031978, 7033660, 1176429, 7643358, 3179743, 2694768, 763525, 4182158, 7004001, 1531454, 5888805, 1140622, 4321431, 7041324, 2756392, 1280050, 6563009, 6107895 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

Since a(21) > 0, M(23) = 8388607 is composite. Mersenne numbers are only prime if a(p-2) = 0.

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(21)= 6563009^2 - 2 mod 8388607 = 6107895

CROSSREFS

Cf. A095847, A003010, A129219, A129220, A129221, A129222, A129223, A129225, A129226, A001348.

Sequence in context: A129221 A129222 A129223 * A129225 A129226 A003010

Adjacent sequences:  A129221 A129222 A129223 * A129225 A129226 A129227

KEYWORD

fini,full,nonn

AUTHOR

Sergio Pimentel (ferdiego(AT)suddenlink.net), Apr 04 2007

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Last modified February 15 10:06 EST 2012. Contains 205763 sequences.