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 A107078 Whether n has non-unitary prime divisors. 10
 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also the characteristic function of the numbers that are not squarefree: A013929. - Enrique Pérez Herrero, Jul 08 2012 The sequence of partial sums of this sequence is A057627. - Jason Kimberley, Feb 01 2017 LINKS Enrique Pérez Herrero, Table of n, a(n) for n = 1..5000 FORMULA a(n) = 1 if A056170(n)>0, 0 otherwise. a(n) = A107079(n) - A013928(n+1). a(n) = 1 - A008966(n). - Reinhard Zumkeller, Oct 03 2008 a(n) = Sum_{k=0..n-1} (mu(n-k-1) mod 2) - Sum_{k=0..n-1} (mu(n-k) mod 2). a(n) = abs(mu(n) - (-1)^omega(n)) = (mu(n) - (-1)^omega(n))^2 = abs(A008683(n) - (-1)^A001221(n)). - Enrique Pérez Herrero, Apr 28 2012 a(n) = 1 - mu(n)^2. - Enrique Pérez Herrero, Jul 08 2012 MATHEMATICA Table[1-MoebiusMu[n]^2, {n, 1, 100}] (* Enrique Pérez Herrero, Jul 08 2012 *) CROSSREFS Cf. A087049. - R. J. Mathar, Aug 24 2008 Cf. A013929, A008683, A008966, A107078. Sequence in context: A160351 A023969 A060039 * A163533 A020987 A072786 Adjacent sequences:  A107075 A107076 A107077 * A107079 A107080 A107081 KEYWORD easy,nonn AUTHOR Paul Barry, May 10 2005 STATUS approved

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Last modified November 18 07:01 EST 2018. Contains 317279 sequences. (Running on oeis4.)