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A318674 Sum of squarefree divisors of n that have an even number of prime factors. 6
1, 1, 1, 1, 1, 7, 1, 1, 1, 11, 1, 7, 1, 15, 16, 1, 1, 7, 1, 11, 22, 23, 1, 7, 1, 27, 1, 15, 1, 32, 1, 1, 34, 35, 36, 7, 1, 39, 40, 11, 1, 42, 1, 23, 16, 47, 1, 7, 1, 11, 52, 27, 1, 7, 56, 15, 58, 59, 1, 32, 1, 63, 22, 1, 66, 62, 1, 35, 70, 60, 1, 7, 1, 75, 16, 39, 78, 72, 1, 11, 1, 83, 1, 42, 86, 87, 88, 23, 1, 32, 92, 47 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
LINKS
FORMULA
a(n) = Sum_{d|n} [A008683(d) > 0]*d.
a(n) = A048250(n) - A318675(n).
For all n >= 1, a(n) <= A318676(n).
PROG
(PARI) A318674(n) = sumdiv(n, d, (1==moebius(d))*d);
CROSSREFS
Sequence in context: A367483 A348281 A317940 * A284118 A165725 A214685
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 04 2018
STATUS
approved

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Last modified May 28 01:34 EDT 2024. Contains 372900 sequences. (Running on oeis4.)