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 A079294 Number of distinct prime factors of the numerator of the 2n-th Bernoulli number. 5
 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 3, 2, 2, 3, 3, 3, 2, 1, 2, 2, 1, 5, 3, 3, 3, 5, 3, 4, 5, 3, 5, 2, 3, 6, 5, 2, 2, 3, 4, 5, 4, 5, 4, 4, 4, 4, 6, 5, 6, 5, 7, 5, 5, 3, 6, 4, 2, 5, 2, 3, 4, 9, 4, 6, 7, 4, 5, 4, 8, 8, 4, 2, 7, 7, 7, 7, 8, 5, 8, 6, 5, 8, 9, 6, 5, 3, 8 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,11 LINKS Amiram Eldar, Table of n, a(n) for n = 0..103 S. S. Wagstaff, Jr., Factors of Bernoulli numbers FORMULA a(n) = A001221(abs(A000367(n))). - Amiram Eldar, Feb 09 2020 MATHEMATICA Table[PrimeNu[Numerator[BernoulliB[2n]]], {n, 0, 30}] (* Amiram Eldar, Feb 09 2020 *) PROG (PARI) a(n)=omega(numerator(bernfrac(2*n))) CROSSREFS Cf. A001221, A000367, A046886. Sequence in context: A309806 A256170 A051686 * A242789 A076733 A079643 Adjacent sequences:  A079291 A079292 A079293 * A079295 A079296 A079297 KEYWORD nonn AUTHOR Benoit Cloitre, Feb 09 2003 EXTENSIONS More terms from T. D. Noe, Feb 13 2004 STATUS approved

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Last modified September 26 01:25 EDT 2020. Contains 337346 sequences. (Running on oeis4.)