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


(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A247717 Numbers n such that A033493(n)/A008908(n) is an integer. 0


%S 1,5,18,58,99,153,176,228,238,240,282,341,345,421,475,585,629,712,739,

%T 779,802,815,974,995,1078,1088,1237,1257,1262,1290,1346,1398,1424,

%U 1459,1673,1694,1724,1731,1802,1811,1916,1928,1988,2170,2222,2260,2272,2275,2317,2365,2397,2410

%N Numbers n such that A033493(n)/A008908(n) is an integer.

%C Equivalently, these are also numbers n such that the average of the numbers in the Collatz (3x+1) iteration of n is an integer.

%o (PARI)

%o Tavg(n)=c=0;s=n;while(n!=1,if(n==Mod(0,2),n=n/2;c++;s+=n);if(n==Mod(1,2)&&n!=1,n=3*n+1;s+=n;c++));s/(c+1)

%o n=1;while(n<10^4,if(floor(Tavg(n))==Tavg(n),print1(n,", "));n++)

%Y Cf. A008908, A033493.

%K nonn

%O 1,2

%A _Derek Orr_, Sep 22 2014

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 24 19:03 EST 2022. Contains 350565 sequences. (Running on oeis4.)