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Least splitter of log(n) and log(n+1).
2

%I #11 Sep 17 2013 06:00:47

%S 1,1,3,2,3,5,1,6,4,3,5,2,5,3,4,5,6,10,18,1,11,8,6,5,4,7,10,3,5,7,9,15,

%T 2,11,7,5,8,14,3,10,7,4,9,5,11,6,7,8,10,12,15,21,34,1,40,24,17,13,11,

%U 10,8,7,13,6,11,5,14,9,17,4,11,7,10,13,22,3,17

%N Least splitter of log(n) and log(n+1).

%C Essentially the same as A183163. - _R. J. Mathar_, Jul 27 2013

%C Suppose that x < y. The least splitter of x and y is introduced at A227631 as the least positive integer d such that x <= c/d < y for some integer c; the number c/d is called the least splitting rational of x and y.

%H Clark Kimberling, <a href="/A227634/b227634.txt">Table of n, a(n) for n = 1..1000</a>

%e The splitting rationals of consecutive numbers log(1), log(2), ... are 0, 1, 4/3, 3/2, 5/3, 9/5, 2, 13/6, 9/4, 7/3, 12/5, 5/2, 13/5; the denominators form A227634, and the numerators, A227684. Chain:

%e log(1) <= 0 < log(2) < 1 < log(3) < 4/3 < log(4) < 3/2 < log(5) < 5/3 < ...

%t h[n_] := h[n] = HarmonicNumber[n]; r[x_, y_] := Module[{c, d}, d = NestWhile[#1 + 1 &, 1, ! (c = Ceiling[#1 x - 1]) < Ceiling[#1 y] - 1 &]; (c + 1)/d]; t = Table[r[Log[n], Log[n + 1]], {n, 1, 120}] (*fractions*)

%t Denominator[t] (* A227634 *)

%t Numerator[t] (* A227684 *)

%Y Cf. A227631.

%K nonn,frac,easy

%O 1,3

%A _Clark Kimberling_, Jul 18 2013