login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A194734 Number of k such that {-k*r} > {-n*r}, where { } = fractional part, r = (1+sqrt(5))/2 (the golden ratio). 2

%I #7 Aug 13 2021 09:37:25

%S 0,0,2,1,0,4,2,7,4,1,8,4,0,9,4,14,8,2,14,7,20,12,4,19,10,1,18,8,26,15,

%T 4,24,12,0,22,9,32,18,4,29,14,40,24,8,36,19,2,32,14,45,26,7,40,20,54,

%U 33,12,48,26,4,42,19,58,34,10,51,26,1,44,18,62,35,8,54,26,73,44

%N Number of k such that {-k*r} > {-n*r}, where { } = fractional part, r = (1+sqrt(5))/2 (the golden ratio).

%C The fractional part here uses the Mma implementation for negative arguments: It is the fractional part of the absolute value, turned negative. So a(n) = A019587(n)-1. - _R. J. Mathar_, Aug 13 2021

%t r = -GoldenRatio; p[x_] := FractionalPart[x];

%t u[n_, k_] := If[p[k*r] <= p[n*r], 1, 0]

%t v[n_, k_] := If[p[k*r] > p[n*r], 1, 0]

%t s[n_] := Sum[u[n, k], {k, 1, n}]

%t t[n_] := Sum[v[n, k], {k, 1, n}]

%t Table[s[n], {n, 1, 100}] (* A019588 *)

%t Table[t[n], {n, 1, 100}] (* A193734 *)

%Y Cf. A019588, A194738.

%K nonn

%O 1,3

%A _Clark Kimberling_, Sep 02 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 18:17 EDT 2024. Contains 371962 sequences. (Running on oeis4.)