login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A194816 Number of integers k in [1,n] such that {n*r+k*r} > {n*r-k*r}, where { } = fractional part and r=sqrt(2). 2

%I

%S 1,1,1,2,3,4,4,4,4,5,6,6,6,6,6,7,8,9,9,9,10,11,12,12,12,12,13,14,15,

%T 16,16,16,17,18,19,19,19,19,20,21,21,21,21,21,22,23,24,24,24,24,25,26,

%U 26,26,26,27,28,29,30,30,30,31,32,33,33,33,33,34,35,35,35,35,35

%N Number of integers k in [1,n] such that {n*r+k*r} > {n*r-k*r}, where { } = fractional part and r=sqrt(2).

%t r = Sqrt[2]; p[x_] := FractionalPart[x];

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

%t v[n_, k_] := If[p[n*r + k*r] > p[n*r - k*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}] (* A194815 *)

%t Table[t[n], {n, 1, 100}] (* A194816 *)

%Y Cf. A194815, A194813.

%K nonn

%O 1,4

%A _Clark Kimberling_, Sep 03 2011

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 24 01:16 EST 2020. Contains 332195 sequences. (Running on oeis4.)