|
| |
|
|
A028393
|
|
Iterate the map in A006368 starting at 8.
|
|
6
| |
|
|
8, 12, 18, 27, 20, 30, 45, 34, 51, 38, 57, 43, 32, 48, 72, 108, 162, 243, 182, 273, 205, 154, 231, 173, 130, 195, 146, 219, 164, 246, 369, 277, 208, 312, 468, 702, 1053, 790, 1185, 889, 667, 500, 750, 1125, 844
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| It is conjectured that this trajectory never repeats, but no proof of this has been found. - N. J. A. Sloane, Jul 14 2009
|
|
|
REFERENCES
| D. Gale, Tracking the Automatic Ant and Other Mathematical Explorations, A Collection of Mathematical Entertainments Columns from The Mathematical Intelligencer, Springer, 1998; see p. 16. [From N. J. A. Sloane, Jul 14 2009]
J. C. Lagarias, ed., The Ultimate Challenge: The 3x+1 Problem, Amer. Math. Soc., 2010; see page 5. [From N. J. A. Sloane, Jan 21 2011]
|
|
|
LINKS
| T. D. Noe, Table of n, a(n) for n=0..1000
Index entries for sequences related to 3x+1 (or Collatz) problem
|
|
|
MAPLE
| F := proc(n) option remember; if n = 0 then 8 elif 3*F(n-1) mod 2 = 0 then 3*F(n-1)/2 else round(3*F(n-1)/4); fi; end; [ seq(F(i), i=0..80) ];
|
|
|
CROSSREFS
| Cf. A006368, A028394, A180864.
Sequence in context: A157940 A087696 A015897 * A066681 A171241 A120137
Adjacent sequences: A028390 A028391 A028392 * A028394 A028395 A028396
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| J. H. Conway (conway(AT)math.princeton.edu)
|
| |
|
|
