OFFSET
0,2
COMMENTS
If the Collatz conjecture is true, then a(n) > 0 for all n >= 0.
LINKS
EXAMPLE
For n = 3 we have:
k T^k(3) T^(2*k)(3)
- ------ ----------
1 10 5
2 5 8
3 16 2
4 8 4
5 4 1
6 2 2
so a(3) = 6.
PROG
(PARI) a(n, T=x->if (x%2, 3*x+1, x/2)) = my (x1=n, x2=n); for (k=1, oo, x1=T(x1); x2=T(T(x2)); if (x1==x2, return (k)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jun 28 2020
STATUS
approved