OFFSET
1,64
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
MATHEMATICA
f[n_] := Plus @@ DeleteDuplicates @ Map[EulerPhi, Divisors[n]]; a[n_] := -2 + Length @ FixedPointList[f, n]; Array[a, 100]
PROG
(Python)
from sympy import totient, divisors
def A348213(n):
c, k = 0, n
m = sum(set(map(totient, divisors(k, generator=True))))
while m != k:
k = m
m = sum(set(map(totient, divisors(k, generator=True))))
c += 1
return c # Chai Wah Wu, Nov 15 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 07 2021
STATUS
approved