Remark.
The best result is now
see D. Applegate and J. C. Lagarias, Density Bounds for the
3x+1
Problem I: Tree-Search Method,
Math. Comp.
, 64, 411-426.
see D. Applegate and J. C. Lagarias, Density Bounds for the 3x+1
Problem I: Tree-Search Method, Math. Comp., 64, 411-426.