**47**
M. S. Klamkin, Problem 63--12,
SIAM Review, 5 (1963) 275--276.
States the problem:
Consider the permutation defined by
,
,
.
Does **n = 8** have an infinite trajectory?
How many finite cycles are there for **f**?
This function was the original one proposed by L. Collatz in 1932
[24].

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