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
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 09 2007
STATUS
approved