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A166142 Row products of A166141; Product of such divisors of n that are squarefree and have an even number of prime factors. 5
1, 1, 1, 1, 1, 6, 1, 1, 1, 10, 1, 6, 1, 14, 15, 1, 1, 6, 1, 10, 21, 22, 1, 6, 1, 26, 1, 14, 1, 900, 1, 1, 33, 34, 35, 6, 1, 38, 39, 10, 1, 1764, 1, 22, 15, 46, 1, 6, 1, 10, 51, 26, 1, 6, 55, 14, 57, 58, 1, 900, 1, 62, 21, 1, 65, 4356, 1, 34, 69, 4900, 1, 6, 1, 74, 15, 38, 77, 6084, 1, 10 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
LINKS
FORMULA
a(n) = Product_{d|n} A080304(d). - Antti Karttunen, Aug 06 2018
EXAMPLE
For n = 30 = 2*3*5, all its divisors [1, 2, 3, 5, 6, 10, 15, 30] are squarefree, but only 1, 6, 10 and 15 have an even number of prime factors, thus a(30) = 1*6*10*15 = 900. - Antti Karttunen, Aug 06 2018
PROG
(PARI) A166142(n) = { my(m=1); fordiv(n, d, m *= if(moebius(d) > 0, d, 1)); (m); }; \\ Antti Karttunen, Aug 06 2018
CROSSREFS
Sequence in context: A080304 A340677 A340679 * A290479 A304404 A290480
KEYWORD
nonn
AUTHOR
Mats Granvik, Oct 08 2009
EXTENSIONS
Alternative definition added to the name by Antti Karttunen, Aug 06 2018
STATUS
approved

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Last modified March 19 06:32 EDT 2024. Contains 370953 sequences. (Running on oeis4.)