login
A116022
n*phi(n)*phi(phi(n)) is a palindrome.
0
1, 2, 3, 4, 309, 618, 9264, 43407
OFFSET
1,2
COMMENTS
No further terms up to 1 million. - Harvey P. Dale, Oct 04 2024
EXAMPLE
43407*phi(43407)*phi(phi(43407)) = 6739855589376.
MATHEMATICA
Select[Range[44000], PalindromeQ[# EulerPhi[#] EulerPhi[EulerPhi[#]]]&] (* Harvey P. Dale, Oct 04 2024 *)
CROSSREFS
Cf. A115891.
Sequence in context: A244548 A004877 A375585 * A172998 A004888 A355439
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 13 2006
STATUS
approved