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A033272 Number of odd nonprimes dividing n. 2
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 1, 2, 2, 2, 1, 1, 3, 2, 1, 2, 1, 1, 2, 1, 1, 4, 1, 2, 2, 1, 1, 2, 2, 1, 2, 1, 1, 4, 1, 2, 2, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

MATHEMATICA

Table[Length[Select[Divisors[n], OddQ[#]&&!PrimeQ[#]&]], {n, 80}] (* Harvey P. Dale, May 06 2012 *)

PROG

(PARI) a(n) = sumdiv(n, d, (d%2) && !isprime(d)); \\ Michel Marcus, May 05 2017

CROSSREFS

Cf. A001227 (with odd divisors), A033273 (with nonprime divisors).

Sequence in context: A300820 A257990 A257743 * A324907 A325133 A236338

Adjacent sequences:  A033269 A033270 A033271 * A033273 A033274 A033275

KEYWORD

nonn

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified April 21 10:03 EDT 2019. Contains 322328 sequences. (Running on oeis4.)