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A034973
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Number of prime factors in central binomial coefficients C(n,[ n/2 ]), the terms of A001405.
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11
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0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 12, 12, 13, 13, 12, 12, 12, 12, 12, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 14, 14, 15, 15, 15, 15, 16
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Sequence is not monotonic. E.g. a(44)=10,a(45)=9 and a(46)=10. The number of prime factors of n! is pi(n), but these numbers are lower.
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..10000
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EXAMPLE
| a(25)=a(C(25,12))=a(520030)=6 because actual prime factors are 2,5,7,17,19,23.
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CROSSREFS
| Cf. A001405, A034974.
Cf. A067434
Sequence in context: A053693 A068063 A087181 * A066927 A060065 A057356
Adjacent sequences: A034970 A034971 A034972 * A034974 A034975 A034976
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KEYWORD
| nonn,easy,nice
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu)
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