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A145097
a(n) is the largest proper divisor of the Mersenne composite A065341(n).
3
89, 178481, 2304167, 616318177, 164511353, 20408568497, 59862819377, 1416003655831, 3203431780337, 761838257287, 10334355636337793, 21514198099633918969, 224958284260258499201, 57912614113275649087721
OFFSET
1,1
COMMENTS
Note that not all the largest divisors are primes.
Which divisors are prime? - see A145099. - Artur Jasinski, Oct 04 2008
LINKS
MATHEMATICA
a = {}; Do[m = 2^Prime[n] - 1; If[PrimeQ[m], null, AppendTo[a, Divisors[m][[ -2]]]], {n, 1, 40}]; a
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Oct 01 2008
EXTENSIONS
Name clarified by Amiram Eldar, Mar 12 2020
STATUS
approved