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A099042 Number of badly sieved (A066680) divisors of n. 5
0, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 2, 1, 4, 1, 2, 2, 2, 1, 4, 1, 2, 2, 2, 2, 4, 1, 2, 2, 3, 1, 3, 1, 2, 3, 2, 1, 4, 1, 3, 2, 2, 1, 4, 2, 3, 2, 2, 1, 5, 1, 2, 3, 2, 2, 3, 1, 2, 2, 4, 1, 5, 1, 2, 3, 2, 2, 3, 1, 4, 2, 2, 1, 4, 2, 2, 2, 3, 1, 6, 2, 2, 2, 2, 2, 4, 1, 3, 2, 3, 1, 3, 1, 3, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

A001221(n) <= a(n) <= A000005(n).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

FORMULA

a(n) = Sum_{d|n} A099104(d). - Antti Karttunen, Jul 02 2018

EXAMPLE

a(24) = #{2,3,8,12} = 4; A099043(24) = 2+3+8+12 = 25;

a(25) = #{5} = 1; A099043(25) = 5;

a(26) = #{2,13} = 2; A099043(26) = 2+13 = 15.

PROG

(PARI)

A099104(n) = if(1==n, 0, my(m=1); fordiv(n, d, if((d<n)&&((d*d)>=n), m *= (1-A099104(d)))); (m));

A099042(n) = sumdiv(n, d, A099104(d)); \\ Antti Karttunen, Jul 02 2018

CROSSREFS

Cf. A066680, A099104.

Sequence in context: A320012 A241276 A292286 * A140774 A056924 A316364

Adjacent sequences:  A099039 A099040 A099041 * A099043 A099044 A099045

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Sep 23 2004

STATUS

approved

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Last modified October 20 05:31 EDT 2018. Contains 316378 sequences. (Running on oeis4.)