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A072358 Number of cubefree numbers <= n which are not squarefree. 2
0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 10, 10, 10, 10, 11, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,9
LINKS
FORMULA
a(n) = A060431(n) - A013928(n+1).
a(n) = Sum_{k=1..n} (A212793(k) * (1 - A008966(k))). - Reinhard Zumkeller, May 27 2012
a(n) ~ c * n, where c = 1/zeta(3) - 1/zeta(2) = A088453 - A059956 = 0.22398... - Amiram Eldar, Feb 16 2021
MATHEMATICA
Accumulate @ Table[Boole[Max @ FactorInteger[n][[;; , 2]] == 2], {n, 1, 100}] (* Amiram Eldar, Feb 16 2021 *)
PROG
(Haskell)
a072358 n = a072358_list !! (n-1)
a072358_list = scanl1 (+) $
zipWith (*) a212793_list $ map (1 -) a008966_list
-- Reinhard Zumkeller, May 27 2012
CROSSREFS
Sequence in context: A238598 A156684 A070564 * A074795 A069577 A282426
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jul 18 2002
STATUS
approved

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Last modified March 28 08:12 EDT 2024. Contains 371236 sequences. (Running on oeis4.)