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A136176 Number of exponents in the prime factorization of n which divide n. 2
0, 1, 1, 1, 1, 2, 1, 0, 0, 2, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 2, 1, 2, 0, 2, 1, 2, 1, 3, 1, 0, 2, 2, 2, 2, 1, 2, 2, 1, 1, 3, 1, 2, 1, 2, 1, 2, 0, 2, 2, 2, 1, 2, 2, 1, 2, 2, 1, 3, 1, 2, 1, 0, 2, 3, 1, 2, 2, 3, 1, 2, 1, 2, 1, 2, 2, 3, 1, 2, 0, 2, 1, 3, 2, 2, 2, 1, 1, 3, 2, 2, 2, 2, 2, 1, 1, 2, 1, 2, 1, 3, 1, 1, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
LINKS
EXAMPLE
128000 = 2^10 * 5^3. 10 divides 128000, but 3 does not. So a(128000) = 1.
MATHEMATICA
Table[Length[Select[Table[FactorInteger[n][[i, 2]], {i, 1, Length[FactorInteger[n]]}], Mod[n, # ] == 0 &]], {n, 1, 90}] (* Stefan Steinerberger, Dec 21 2007 *)
PROG
(PARI) A136176(n)=sum(j=1, #t=factor(n)[, 2]~, !(n%t[j])) \\ M. F. Hasler, Dec 21 2007
CROSSREFS
Cf. A136177.
Sequence in context: A323090 A355935 A180026 * A291914 A303708 A319138
KEYWORD
nonn,easy
AUTHOR
Leroy Quet, Dec 19 2007
EXTENSIONS
More terms from M. F. Hasler and Stefan Steinerberger, Dec 21 2007
STATUS
approved

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Last modified March 28 17:25 EDT 2024. Contains 371254 sequences. (Running on oeis4.)