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A348215
a(n) is the sum of the iterated A348158 starting from n until a fixed point is reached.
2
0, 1, 0, 3, 0, 3, 0, 7, 0, 5, 0, 7, 0, 7, 0, 15, 0, 9, 0, 15, 0, 11, 0, 15, 0, 13, 0, 21, 0, 15, 0, 31, 0, 17, 0, 25, 0, 19, 0, 31, 0, 21, 0, 33, 0, 23, 0, 31, 0, 25, 0, 39, 0, 27, 0, 49, 0, 29, 0, 31, 0, 31, 57, 120, 0, 33, 0, 51, 0, 35, 0, 57, 0, 37, 0, 57
OFFSET
1,4
COMMENTS
The first odd number k with a(k) > 0 is k = 63.
LINKS
FORMULA
a(n) = 0 if and only if n is in A326835.
a(2*n) > 0 for all n.
EXAMPLE
a(4) = 3 since the iterations of the map x -> A348158(x) starting from 4 are 4 -> 3.
a(64) = 120 since the iterations of the map x -> A348158(x) starting from 64 are 64 -> 63 -> 57, and 63 + 57 = 120.
MATHEMATICA
f[n_] := Plus @@ DeleteDuplicates @ Map[EulerPhi, Divisors[n]]; a[n_] := Plus @@ Most @ FixedPointList[f, n] - n; Array[a, 100]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 07 2021
STATUS
approved