cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A154131 Numbers n such that the fractional part of (4/3)^n is less than 1/n.

This page as a plain text file.
%I A154131 #11 Sep 03 2016 17:07:14
%S A154131 1,4,17,1738,1739,12863,15705,109705,174894,289047,720429,2087694,
%T A154131 2087695,4475944,6968999
%N A154131 Numbers n such that the fractional part of (4/3)^n is less than 1/n.
%C A154131 Numbers n such that fract((4/3)^n) < 1/n, where fract(x) = x - floor(x).
%C A154131 The next term is greater than 3*10^8.
%e A154131 a(3)=17 since fract((4/3)^17) = 0.03273... < 1/17, but fract((4/3)^k) >= 1/k for 5 <= k <= 16.
%t A154131 Select[Range[1000], N[FractionalPart[(4/3)^#], 100] < (1/#) &] (* _G. C. Greubel_, Sep 02 2016 *)
%o A154131 (PARI) isok(n) = frac((4/3)^n) < 1/n; \\ _Michel Marcus_, Sep 03 2016
%Y A154131 Cf. A153662, A153670, A153702, A137994, A154139, A154147.
%Y A154131 Cf. A002379, A064628.
%K A154131 nonn,more
%O A154131 1,2
%A A154131 _Hieronymus Fischer_, Jan 11 2009
%E A154131 a(10)-a(15) from _Robert Gerbicz_, Nov 21 2010