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A365368
First integer > n reached under iteration of map x -> (5/3)*round(x) when started at n, or -1 if no such integer is ever reached.
4
5, 5, 5, 20, 10245, 10, 20, 10245, 15, 130, 30, 20, 10245, 105, 25, 45, 130, 30, 245, 55, 35, 10245, 105, 40, 70, 120, 45, 130, 80, 50, 145, 245, 55, 95, 270, 60, 10245, 105, 65, 520, 870, 70, 120, 2605, 75, 355, 130, 80, 380, 230, 85, 145, 245, 90, 255, 155, 95
OFFSET
1,1
COMMENTS
Conjecture: an integer will always be reached, i.e. a(n) > 0 for all n.
PROG
(Python)
from fractions import Fraction
def A365368(n):
x = Fraction(n)
while x.denominator > 1 or x<=n:
x = Fraction(5*x.__round__(), 3)
return int(x)
KEYWORD
nonn
AUTHOR
Chai Wah Wu, Sep 02 2023
STATUS
approved