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A072047 Number of prime factors of the squarefree numbers: omega(A005117(n)). 14
0, 1, 1, 1, 2, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 2, 2, 1, 3, 1, 2, 1, 2, 1, 2, 2, 2, 1, 1, 2, 2, 3, 1, 2, 3, 1, 1, 2, 2, 3, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 1, 1, 3, 1, 3, 2, 1, 1, 3, 2, 1, 3, 2, 2, 2, 2, 2, 1, 2, 3, 1, 2, 2, 1, 3, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

a(n) = A001221(A005117(n)) = A001222(A005117(n)).

For n > 1: length of row n in A265668. - Reinhard Zumkeller, Dec 13 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

MATHEMATICA

PrimeOmega[Select[Range[200], SquareFreeQ]] (* Harvey P. Dale, May 14 2011 *)

PROG

(Haskell)

a072047 n = a072047_list !! (n-1)

a072047_list = map a001221 $ a005117_list

-- Reinhard Zumkeller, Aug 08 2011

CROSSREFS

Cf. A072048.

Cf. A001221, A001222, A005117, A265668.

Sequence in context: A192013 A329618 A026517 * A327521 A282870 A106802

Adjacent sequences:  A072044 A072045 A072046 * A072048 A072049 A072050

KEYWORD

nonn,nice

AUTHOR

Reinhard Zumkeller, Jun 09 2002

STATUS

approved

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Last modified April 13 19:42 EDT 2021. Contains 342941 sequences. (Running on oeis4.)