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A329484 Dirichlet convolution of the Louiville function with itself. 1
1, -2, -2, 3, -2, 4, -2, -4, 3, 4, -2, -6, -2, 4, 4, 5, -2, -6, -2, -6, 4, 4, -2, 8, 3, 4, -4, -6, -2, -8, -2, -6, 4, 4, 4, 9, -2, 4, 4, 8, -2, -8, -2, -6, -6, 4, -2, -10, 3, -6, 4, -6, -2, 8, 4, 8, 4, 4, -2, 12, -2, 4, -6, 7, 4, -8, -2, -6, 4, -8, -2, -12, -2
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OFFSET
1,2
COMMENTS
Up to sign this sequence partitions the positive integers in the same way asA008836.Additional interesting partitions exist when values of this sequence are taken into account.
LINKS
Eric Weisstein's World of Mathematics,Liouville Function.
FORMULA
a(n) = Sum_{d|n}A008836(d) *A008836(n/d).
a(n) = tau(n) * lambda(n) =A000005(n) *A008836(n). -Enrique Pérez Herrero,Sep 15 2020
Multiplicative with a(p^e) = (e+1)*(-1)^e, p prime. -Enrique Pérez Herrero,Sep 20 2020
Dirichlet g.f.: zeta(2*s)^2/zeta(s)^2. -Amiram Eldar,Dec 05 2022
MATHEMATICA
a[n_]:= DivisorSum[n, LiouvilleLambda[#] * LiouvilleLambda[n/#] &]; Array[a, 100] (*Amiram Eldar,Jan 18 2020 *)
PROG
(PARI) a(n) = sumdiv(n, d, (-1)^big Omega (d) * (-1)^big Omega (n/d))
(PARI) a(n) = {numdiv(n)*(-1)^big Omega (n)} \\Andrew Howroyd,Sep 15 2020
(Python)
from math import prod
from sympy import factorint
defA329484(n): return prod(-e-1 if e&1 else e+1 for e in factorint(n).values()) #Chai Wah Wu,Dec 23 2022
CROSSREFS
KEYWORD
sign,mult
AUTHOR
Torlach Rush,Jan 17 2020
STATUS
approved

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Last modified September 18 15:25 EDT 2024. Contains 376000 sequences. (Running on oeis4.)