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A333871
Sum of the iterated absolute Möbius divisor function (A173557).
3
0, 1, 3, 1, 5, 3, 9, 1, 3, 5, 15, 3, 15, 9, 9, 1, 17, 3, 21, 5, 15, 15, 37, 3, 5, 15, 3, 9, 37, 9, 39, 1, 25, 17, 27, 3, 39, 21, 27, 5, 45, 15, 57, 15, 9, 37, 83, 3, 9, 5, 33, 15, 67, 3, 45, 9, 39, 37, 95, 9, 69, 39, 15, 1, 51, 25, 91, 17, 59, 27, 97, 3, 75, 39
OFFSET
1,3
COMMENTS
Analogous to A092693 with the absolute Möbius divisor function (A173557) instead of the Euler totient function phi (A000010).
LINKS
Daeyeoul Kim, Umit Sarp, and Sebahattin Ikikardes, Iterating the Sum of Möbius Divisor Function and Euler Totient Function, Mathematics, Vol. 7, No. 11 (2019), pp. 1083-1094.
EXAMPLE
a(3) = A173557(3) + A173557(A173557(3)) = 2 + 1 = 3.
MATHEMATICA
f[p_, e_] := p - 1; u[1] = 1; u[n_] := Times @@ (f @@@ FactorInteger[n]); a[n_] := Plus @@ FixedPointList[u, n] - n - 1 ; Array[a, 100]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 08 2020
STATUS
approved