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.

Previous Showing 31-33 of 33 results.

A194734 Number of k such that {-k*r} > {-n*r}, where { } = fractional part, r = (1+sqrt(5))/2 (the golden ratio).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Sep 02 2011

Keywords

Comments

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

Crossrefs

Cf. A019588, A194738.

Programs

  • Mathematica
    r = -GoldenRatio; p[x_] := FractionalPart[x];
u[n_, k_] := If[p[k*r] <= p[n*r], 1, 0]
v[n_, k_] := If[p[k*r] > p[n*r], 1, 0]
s[n_] := Sum[u[n, k], {k, 1, n}]
t[n_] := Sum[v[n, k], {k, 1, n}]
Table[s[n], {n, 1, 100}]   (* A019588 *)
Table[t[n], {n, 1, 100}]   (* A193734 *)

A194739 Number of k such that {k*sqrt(3)} > {n*sqrt(3)}, where { } = fractional part.

Original entry on oeis.org

0, 1, 2, 0, 2, 4, 6, 1, 4, 7, 10, 2, 6, 10, 0, 5, 10, 15, 2, 8, 14, 20, 4, 11, 18, 25, 6, 14, 22, 1, 10, 19, 28, 4, 14, 24, 34, 7, 18, 29, 40, 10, 22, 34, 2, 15, 28, 41, 6, 20, 34, 48, 10, 25, 40, 0, 16, 32, 48, 5, 22, 39, 56, 10, 28, 46, 64, 15, 34, 53, 2, 22, 42, 62, 8
Offset: 1

Views

Author

Clark Kimberling, Sep 02 2011

Keywords

Crossrefs

Cf. A194738.

Programs

  • Mathematica
    r = Sqrt[3]; p[x_] := FractionalPart[x];
u[n_, k_] := If[p[k*r] <= p[n*r], 1, 0]
v[n_, k_] := If[p[k*r] > p[n*r], 1, 0]
s[n_] := Sum[u[n, k], {k, 1, n}]
t[n_] := Sum[v[n, k], {k, 1, n}]
Table[s[n], {n, 1, 100}]   (* A194738 *)
Table[t[n], {n, 1, 100}]   (* A194739 *)

A194814 Number of integers k in [1,n] such that {n*r+k*r} > {n*r-k*r}, where { } = fractional part and r=(1+sqrt(5))/2 (the golden ratio).

Original entry on oeis.org

1, 2, 2, 2, 3, 4, 4, 4, 4, 5, 6, 6, 7, 8, 9, 9, 9, 10, 11, 11, 11, 11, 12, 12, 12, 13, 14, 15, 15, 15, 16, 17, 17, 18, 19, 20, 20, 20, 21, 22, 22, 22, 22, 23, 23, 23, 24, 25, 26, 26, 26, 27, 28, 28, 28, 28, 29, 29, 29, 30, 31, 31, 31, 31, 32, 33, 33, 34, 35, 36, 36, 36
Offset: 1

Views

Author

Clark Kimberling, Sep 03 2011

Keywords

Comments

A194813+A194814=A000027 for n>0.

Examples

			{4r+1r}=0.09...; {4r-1r}=0.85...;
{4r+2r}=0.70...; {4r-2r}=0.23...;
{4r+3r}=0.32...; {4r-3r}=0.61...;
{4r+4r}=0.94...; {4r-4r}=0.00...;
so that a(4)=2.

Crossrefs

Cf. A194813, A194738.

Programs

  • Mathematica
    r = GoldenRatio; p[x_] := FractionalPart[x];
u[n_, k_] := If[p[n*r + k*r] <= p[n*r - k*r], 1, 0]
v[n_, k_] := If[p[n*r + k*r] > p[n*r - k*r], 1, 0]
s[n_] := Sum[u[n, k], {k, 1, n}]
t[n_] := Sum[v[n, k], {k, 1, n}]
Table[s[n], {n, 1, 100}]   (* A194813 *)
Table[t[n], {n, 1, 100}]   (* A194814 *)
Previous Showing 31-33 of 33 results.

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