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A154131
Numbers n such that the fractional part of (4/3)^n is less than 1/n.
1
1, 4, 17, 1738, 1739, 12863, 15705, 109705, 174894, 289047, 720429, 2087694, 2087695, 4475944, 6968999
OFFSET
1,2
COMMENTS
Numbers n such that fract((4/3)^n) < 1/n, where fract(x) = x - floor(x).
The next term is greater than 3*10^8.
EXAMPLE
a(3)=17 since fract((4/3)^17) = 0.03273... < 1/17, but fract((4/3)^k) >= 1/k for 5 <= k <= 16.
MATHEMATICA
Select[Range[1000], N[FractionalPart[(4/3)^#], 100] < (1/#) &] (* _G. C. Greubel_, Sep 02 2016 *)
PROG
(PARI) isok(n) = frac((4/3)^n) < 1/n; \\ _Michel Marcus_, Sep 03 2016
KEYWORD
nonn,more
AUTHOR
_Hieronymus Fischer_, Jan 11 2009
EXTENSIONS
a(10)-a(15) from _Robert Gerbicz_, Nov 21 2010
STATUS
approved