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A329153
Sum of the iterated unitary totient function (A047994).
3
0, 1, 3, 6, 10, 3, 9, 16, 24, 10, 20, 9, 21, 9, 24, 39, 55, 24, 42, 21, 21, 20, 42, 23, 47, 21, 47, 42, 70, 24, 54, 85, 41, 55, 47, 47, 83, 42, 47, 70, 110, 21, 63, 54, 117, 42, 88, 54, 102, 47, 117, 83, 135, 47, 110, 63, 83, 70, 128, 47, 107, 54, 102, 165, 102
OFFSET
1,3
COMMENTS
Analogous to A092693 with the unitary totient function uphi instead of the Euler totient function phi (A000010).
LINKS
FORMULA
a(n) = n for n in A286067.
EXAMPLE
a(4) = uphi(4) + uphi(uphi(4)) + uphi(uphi(uphi(4))) = 3 + 2 + 1 = 6.
MATHEMATICA
uphi[1] = 1; uphi[n_] := Times @@ (-1 + Power @@@ FactorInteger[n]); Table[Plus @@ FixedPointList[uphi, n] - n - 1, {n, 1, 100}]
KEYWORD
nonn
AUTHOR
Amiram Eldar, Feb 25 2020
STATUS
approved