

A290793


Carmichael numbers n such that Euler totient function of n (phi(n)) is a cube.


2



63973, 18162001, 26921089, 133205761, 225745345, 490503601, 496050841, 698548201, 1031750401, 1100674561, 1384157161, 2178944461, 3805181281, 11351100241, 12648201841, 26498875681, 26542598401, 28553256865, 28645206001, 37590868801, 39866123377, 40527674881
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OFFSET

1,1


COMMENTS

Banks proved that for each positive integer N there are an infinite number of Carmichael numbers whose Euler totient function value is an Nth power. Therefore this sequence is infinite.
The terms were calculated using Pinch's tables of Carmichael numbers (see link below).


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..2942 (terms below 10^18)
William D. Banks, Carmichael Numbers with a Square Totient, Canadian Mathematical Bulletin, Vol. 52, No. 1 (2009), pp. 38.
R. G. E. Pinch, Tables relating to Carmichael numbers.


EXAMPLE

phi(63973) = 36^3.


MATHEMATICA

With[{s = Import["b002997.txt", "Data"][[All, 1]]}, Select[s, IntegerQ@ Power[EulerPhi@ #, 1/3] &]] (* Michael De Vlieger, Aug 14 2017, using bfile at A002997 *)


CROSSREFS

Intersection of A002997 (Carmichael numbers) and A039771.
Cf. A000010, A000578, A272798.
Sequence in context: A214758 A265827 A212882 * A182518 A317136 A182089
Adjacent sequences: A290790 A290791 A290792 * A290794 A290795 A290796


KEYWORD

nonn


AUTHOR

Amiram Eldar, Aug 10 2017


STATUS

approved



