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A181186
Number of prime factors of (2^n - 1) * n! + 1, counted with multiplicity.
1
1, 1, 1, 2, 2, 1, 3, 3, 2, 2, 3, 2, 3, 5, 3, 2, 1, 3, 2, 2, 3, 3, 2, 6, 1, 4, 4, 3, 3, 3, 2, 2, 4, 3, 5, 2, 4, 2, 4, 1, 4, 4, 3, 3, 1, 3, 4, 5, 3, 4, 4, 5, 2, 2, 2, 6, 4, 2, 5, 3, 7, 4, 3, 2, 5, 3, 4, 4, 4, 2, 7, 6, 7, 3, 5, 2, 4, 3, 8, 8, 6, 4
OFFSET
1,4
COMMENTS
a(101) >= 3. See link to factordb.com. - Hugo Pfoertner, Aug 07 2019
LINKS
Yurii Ivanov, Table of n, a(n) for n = 1..103 (terms 1..100 from Sean A. Irvine and Hugo Pfoertner, term 101 from Tyler Busby)
factordb.com, Status of (2^n-1)*n!+1.
FORMULA
a(n) = A001222(A052589(n)+1). - Michel Marcus, Apr 08 2023
MATHEMATICA
Table[PrimeOmega[(2^n-1)n!+1], {n, 90}] (* The program takes a long time to run. *) (* Harvey P. Dale, Feb 10 2019 *)
CROSSREFS
Sequence in context: A193739 A345032 A182535 * A364197 A097291 A269501
KEYWORD
nonn
AUTHOR
Jason Earls, Oct 09 2010
EXTENSIONS
More terms from Sean A. Irvine, Sep 15 2012
STATUS
approved