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 A162296 Sum of divisors of n that have a square factor. 24
 0, 0, 0, 4, 0, 0, 0, 12, 9, 0, 0, 16, 0, 0, 0, 28, 0, 27, 0, 24, 0, 0, 0, 48, 25, 0, 36, 32, 0, 0, 0, 60, 0, 0, 0, 79, 0, 0, 0, 72, 0, 0, 0, 48, 54, 0, 0, 112, 49, 75, 0, 56, 0, 108, 0, 96, 0, 0, 0, 96, 0, 0, 72, 124, 0, 0, 0, 72, 0, 0, 0, 183, 0, 0, 100, 80, 0, 0, 0, 168, 117, 0, 0, 128, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Note that 1 does not have a square factor. - Antti Karttunen, Nov 20 2017 LINKS Antti Karttunen, Table of n, a(n) for n = 1..16384 FORMULA a(n) + A048250(n) = A000203(n). - Antti Karttunen, Nov 20 2017 EXAMPLE a(8) = 12 = 4 + 8. MATHEMATICA Array[DivisorSum[#, # &, # (1 - MoebiusMu[#]^2) == # &] &, 86] (* Michael De Vlieger, Nov 20 2017 *) a[1]=0; a[n_] := DivisorSigma[1, n] - Times@@(1+FactorInteger[n][[;; , 1]]); Array[a, 86] (* Amiram Eldar, Dec 20 2018 *) PROG (PARI) a(n)=sumdiv(n, d, d*(1-moebius(d)^2)); v=vector(300, n, a(n)) CROSSREFS Cf. A000203, A005117, A048250. Sequence in context: A126849 A284117 A183099 * A169773 A236380 A298825 Adjacent sequences:  A162293 A162294 A162295 * A162297 A162298 A162299 KEYWORD easy,nonn AUTHOR Joerg Arndt, Jun 30 2009 STATUS approved

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Last modified May 9 06:30 EDT 2021. Contains 343692 sequences. (Running on oeis4.)