A333871 Sum of the iterated absolute Möbius divisor function (A173557).

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

Amiram Eldar, Table of n, a(n) for n = 1..10000

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

Cf. A092693, A173557, A333870.

Sequence in context: A200498 A227361 A318726 * A364034 A212641 A195835

Adjacent sequences: A333868 A333869 A333870 * A333872 A333873 A333874

Keyword

nonn

Author

Amiram Eldar, Apr 08 2020

Status

approved