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A359586 Inverse Möbius transform of A359581. 2
1, 2, 0, 3, 0, 0, 2, 4, 1, 0, 2, 0, 2, 4, 0, 5, 0, 2, 0, 0, 0, 4, 0, 0, 1, 4, 0, 6, 0, 0, 0, 6, 0, 0, 0, 3, 0, 0, 0, 0, 2, 0, 2, 6, 0, 0, 2, 0, 3, 2, 0, 6, 0, 0, 0, 8, 0, 0, 2, 0, 0, 0, 2, 7, 0, 0, 2, 0, 0, 0, 2, 4, 0, 0, 0, 0, 4, 0, 2, 0, 1, 4, 0, 0, 0, 4, 0, 8, 0, 0, 4, 0, 0, 4, 0, 0, 2, 6, 2, 3, 0, 0, 0, 8, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Multiplicative because A359581 is.
LINKS
FORMULA
a(n) = Sum_{d|n} A359581(d).
From Amiram Eldar, Oct 23 2023: (Start)
Multiplicative with a(p^e) = e+1 if A329697(p) is even, and if A329697(p) is odd, 0 if e is odd and 1 if e is even.
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Product_{p prime} p/(p-(-1)^A329697(p)) = 1.4128... . (End)
MATHEMATICA
A329697[n_] := Length@ NestWhileList[# - #/FactorInteger[#][[-1, 1]] &, n, # != 2^IntegerExponent[#, 2] &] - 1;
f[p_, e_] := If[EvenQ[A329697[p]], e + 1, If[OddQ[e], 0, 1]]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 23 2023 *)
PROG
(PARI)
A329697(n) = if(!bitand(n, n-1), 0, 1+A329697(n-(n/vecmax(factor(n)[, 1]))));
A359581(n) = ((-1)^A329697(n));
A359586(n) = sumdiv(n, d, A359581(d));
CROSSREFS
Sequence in context: A141700 A345228 A357887 * A035205 A357761 A284823
KEYWORD
nonn,mult
AUTHOR
Antti Karttunen, Jan 07 2023
STATUS
approved

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Last modified August 2 12:52 EDT 2024. Contains 374848 sequences. (Running on oeis4.)