OFFSET
1,2
LINKS
FORMULA
a(n) = A114076(n)^2. - Amiram Eldar, Oct 27 2022
MATHEMATICA
Select[Range[20000]^2, IntegerQ[Surd[EulerPhi[#], 3]] &] (* Amiram Eldar, Oct 27 2022 *)
PROG
(Python)
from sympy.ntheory.factor_ import totient
from gmpy2 import *
def isok(k):
if is_square(k):
j = isqrt(k)
a, b = iroot(totient(j) * j, 3)
return b
(PARI) isok(k) = issquare(k) && ispower(eulerphi(k), 3); \\ Michel Marcus, Oct 27 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Darío Clavijo, Oct 27 2022
STATUS
approved