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A135977 Mersenne composites (A065341) with exactly 3 prime factors. 8
536870911, 8796093022207, 140737488355327, 9007199254740991, 2361183241434822606847, 9444732965739290427391, 604462909807314587353087 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..42

FORMULA

a(n) = 2^A344515(n) - 1. - Amiram Eldar, May 23 2021

MATHEMATICA

k = {}; Do[If[ ! PrimeQ[2^Prime[n] - 1], c = FactorInteger[2^Prime[n] - 1]; d = Length[c]; If[d == 3, AppendTo[k, 2^Prime[n] - 1]]], {n, 1, 40}]; k

CROSSREFS

Subsequence of A065341.

Cf. A000225, A054723, A134852, A135975, A135976, A135978, A135979, A344515.

Sequence in context: A319937 A186092 A034617 * A011579 A122970 A204779

Adjacent sequences:  A135974 A135975 A135976 * A135978 A135979 A135980

KEYWORD

nonn

AUTHOR

Artur Jasinski, Dec 09 2007

STATUS

approved

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Last modified October 20 03:04 EDT 2021. Contains 348099 sequences. (Running on oeis4.)