login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A055970 Nonprime numbers k such that k | sigma_3(k) + phi(k)^3. 2

%I #14 Jan 09 2020 03:07:19

%S 1,195,366,735,780,810,860,1070,1692,2940,3135,5535,6076,7344,13194,

%T 15980,20320,37638,47520,54216,62296,89964,95208,121770,135540,135681,

%U 138278,138456,140228,140284,158598,161602,162432,189777,205400,268380

%N Nonprime numbers k such that k | sigma_3(k) + phi(k)^3.

%H Amiram Eldar, <a href="/A055970/b055970.txt">Table of n, a(n) for n = 1..269</a> (terms below 10^10)

%t Do[ If[ !PrimeQ[ n ], If[ Mod[ DivisorSigma[ 3, n ]+EulerPhi[ n ]^3, n ]==0, Print[ n ] ] ], {n, 1, 500000} ]

%Y Cf. A000010, A001158, A055697.

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Jul 19 2000

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 30 23:49 EDT 2024. Contains 374771 sequences. (Running on oeis4.)