A080842 Numbers in the x/3 + 1 conjecture: Repeat until 1 is reached: if x is divisible by 3 then divide by 3, otherwise add 1.
1, 3, 1, 1, 5, 6, 2, 3, 1, 6, 2, 3, 1, 2, 3, 1, 8, 9, 3, 1, 9, 3, 1, 3, 1, 11, 12, 4, 5, 6, 2, 3, 1, 12, 4, 5, 6, 2, 3, 1, 4, 5, 6, 2, 3, 1, 14, 15, 5, 6, 2, 3, 1, 15, 5, 6, 2, 3, 1, 5, 6, 2, 3, 1, 17, 18, 6, 2, 3, 1, 18, 6, 2, 3, 1, 6, 2, 3, 1, 20, 21, 7, 8, 9, 3, 1, 21, 7, 8, 9, 3, 1, 7, 8, 9, 3, 1, 23, 24
Offset: 1
Examples
The trajectories starting at x=2, 3, 4 etc. are (3,1), (1), (5,6,2,3,1), (6,2,3,1), (2,3,1), (8,9,3,1) etc. Each "1" marks the end of a trajectory.
Programs
-
Mathematica
Join[{1},Flatten[Table[Rest[NestWhileList[If[Divisible[#,3],#/3,#+1]&,n, #!=1&]],{n,2,30}]]] (* Harvey P. Dale, Feb 02 2012 *) -
PARI
mult3p1(n, p) = { print1(1" "); for(j=1, n, x=j; while(x>1, if(x%3==0, x/=3, x = x*p+1 ) ; print1(x" ") ; ); ) ; print1(" ") ; } { mult3p1(30,1) ; } - R. J. Mathar, Feb 01 2008
Extensions
Edited and corrected by R. J. Mathar, Feb 01 2008
Comments