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A341444 Dirichlet inverse of A083399, where A083399(n) = 1 + omega(n). 2
1, -2, -2, 2, -2, 5, -2, -2, 2, 5, -2, -7, -2, 5, 5, 2, -2, -7, -2, -7, 5, 5, -2, 9, 2, 5, -2, -7, -2, -16, -2, -2, 5, 5, 5, 14, -2, 5, 5, 9, -2, -16, -2, -7, -7, 5, -2, -11, 2, -7, 5, -7, -2, 9, 5, 9, 5, 5, -2, 30, -2, 5, -7, 2, 5, -16, -2, -7, 5, -16, -2, -23, -2, 5, -7, -7, 5, -16, -2, -11, 2, 5, -2, 30, 5, 5, 5, 9, -2, 30, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The Dirichlet inverse function, a(n) = (omega + 1)^(-1)(n). - Original name.
LINKS
Carl-Erik Fröberg, On the prime zeta function, BIT Numerical Mathematics, Vol. 8, No. 3 (1968), pp. 187-202.
H. Hwang and S. Janson, A central limit theorem for random ordered factorizations of integers, Electron. J. Probab., 16(12):347-361, 2011.
M. D. Schmidt, New characterizations of the summatory function of the Moebius function, arXiv:2102.05842 [math.NT], 2021.
FORMULA
a(n) = (-1)^A001222(n)*Sum_{d | n} A008683(n/d)^2*A008480(d).
a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A083399(n/d) * a(d). - Antti Karttunen, Jul 21 2022
MATHEMATICA
a[1] = 1; a[n_] := a[n] = -DivisorSum[n, (PrimeNu[n/#] + 1)*a[#] &, # < n &]; Array[a, 100] (* Amiram Eldar, Jul 21 2022 *)
PROG
(PARI) cOmega(n) = if (n==1, 1, my(f=factor(n)); bigomega(n)!*prod(k=1, #f~, 1/f[k, 2]!)); \\ A008480
a(n) = (-1)^bigomega(n)*sumdiv(n, d, moebius(n/d)^2*cOmega(d));
(PARI)
memoA341444 = Map();
A341444(n) = if(1==n, 1, my(v); if(mapisdefined(memoA341444, n, &v), v, v = -sumdiv(n, d, if(d<n, (1+omega(n/d))*A341444(d), 0)); mapput(memoA341444, n, v); (v))); \\ Antti Karttunen, Jul 21 2022~
CROSSREFS
Dirichlet inverse of A083399.
Cf. A001221, A001222, A008480, A008683, A008966, A341472 (partial sums).
Cf. also A334743.
Sequence in context: A103512 A130086 A337228 * A084731 A066180 A123487
KEYWORD
sign
AUTHOR
Michel Marcus, Feb 12 2021
EXTENSIONS
Data section extended up to a(91) and name edited by Antti Karttunen, Jul 21 2022
STATUS
approved

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Last modified July 22 19:56 EDT 2024. Contains 374540 sequences. (Running on oeis4.)