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A125029
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a(n) = number of exponents in the prime-factorization of n which are noncomposite.
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1
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0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 2, 0, 1, 2, 1, 2, 2, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 1, 3, 1, 2, 2, 0, 2, 3, 1, 2, 2, 3, 1, 2, 1, 2, 2, 2, 2, 3, 1, 1, 0, 2, 1, 3, 2, 2, 2, 2, 1, 3, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 1, 3, 1, 2, 3
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,6
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EXAMPLE
| a(720) = 2, since the prime-factorization of 720 is 2^4 *3^2 *5^1 and 2 of the exponents in this factorization are non-composites (the exponents 2 and 1).
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MATHEMATICA
| f[n_] := Length @ Select[Last /@ FactorInteger[n], # == 1 || PrimeQ[ # ] &]; Table[f[n], {n, 110}] (*Chandler*)
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CROSSREFS
| Cf. A125030.
Sequence in context: A126864 A124766 A103765 * A062893 A158210 A087802
Adjacent sequences: A125026 A125027 A125028 * A125030 A125031 A125032
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet, Nov 16 2006
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EXTENSIONS
| Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 19 2006
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