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A229344 Mertens's function of the arithmetic derivative of n: a(n) = M(n'), a(1) = 0. 3
0, 1, 1, -1, 1, -2, 1, -2, -1, -2, 1, -1, 1, -2, -2, -4, 1, -2, 1, -2, -1, -3, 1, -3, -1, -1, -1, -4, 1, -4, 1, -4, -2, -3, -2, -1, 1, -2, -1, -2, 1, -1, 1, -3, 0, -2, 1, -4, -2, -3, -3, -2, 1, -4, -1, -1, -1, -4, 1, -1, 1, -3, -2, -5, -2, -2, 1, -3, -1, -1, 1, -1, 1, 0, -2, -4, -2, -3, 1, -4, -3, -3, 1, -1, -1, -3, -4, -4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,6
COMMENTS
a(1) = 0 by convention. - Antti Karttunen, Nov 01 2017
LINKS
FORMULA
a(1) = 0 and for n > 1, a(n) = A002321(A003415(n)).
EXAMPLE
For n=4, M(n') = M(4') = M(4) = -1.
For n=7, M(n') = M(7') = M(1) = 1.
MATHEMATICA
Array[Total@ Map[MoebiusMu, Range@ If[Abs@ # < 2, 0, # Total[#2/#1 & @@@ FactorInteger[Abs@ #]]]] &, 89] (* Michael De Vlieger, Nov 01 2017 *)
PROG
(PARI) rd(n) = {local(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]; )); }
a(n) = mertens(rd(n)); \\ Michel Marcus, Sep 24 2013
(PARI)
A002321(n) = sum(k=1, n, moebius(k));
A003415(n) = { my(fac); if(n<1, 0, fac=factor(n); sum(i=1, matsize(fac)[1], n*fac[i, 2]/fac[i, 1]))}; \\ From Michael B. Porter, Nov 25 2009
A229344(n) = if(1==n, 0, A002321(A003415(n))); \\ Antti Karttunen, Nov 01 2017
CROSSREFS
Sequence in context: A306446 A100387 A322869 * A210501 A307781 A356112
KEYWORD
sign
AUTHOR
Luca Brigada Villa, Sep 24 2013
EXTENSIONS
Description and formula clarified and more terms added by Antti Karttunen, Nov 01 2017
STATUS
approved

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Last modified June 18 15:47 EDT 2024. Contains 373481 sequences. (Running on oeis4.)