A116022 - OEIS

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A116022

n*phi(n)*phi(phi(n)) is a palindrome.

0

1, 2, 3, 4, 309, 618, 9264, 43407

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OFFSET

1,2

COMMENTS

No further terms up to 1 million. - Harvey P. Dale, Oct 04 2024

LINKS

Table of n, a(n) for n=1..8.

EXAMPLE

43407*phi(43407)*phi(phi(43407)) = 6739855589376.

MATHEMATICA

Select[Range[44000], PalindromeQ[# EulerPhi[#] EulerPhi[EulerPhi[#]]]&] (* Harvey P. Dale, Oct 04 2024 *)

CROSSREFS

Sequence in context: A244548 A004877 A375585 * A172998 A004888 A355439

Adjacent sequences: A116019 A116020 A116021 * A116023 A116024 A116025

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, Feb 13 2006

STATUS

approved