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.

A194738 Number of k such that {k*sqrt(3)} < {n*sqrt(3)}, where { } = fractional part.

Original entry on oeis.org

1, 1, 1, 4, 3, 2, 1, 7, 5, 3, 1, 10, 7, 4, 15, 11, 7, 3, 17, 12, 7, 2, 19, 13, 7, 1, 21, 14, 7, 29, 21, 13, 5, 30, 21, 12, 3, 31, 21, 11, 1, 32, 21, 10, 43, 31, 19, 7, 43, 30, 17, 4, 43, 29, 15, 56, 41, 26, 11, 55, 39, 23, 7, 54, 37, 20, 3, 53, 35, 17, 69, 50, 31, 12, 67
Offset: 1

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Author

Clark Kimberling, Sep 02 2011

Keywords

Comments

Related sequences:
A019587, A194733, A019588, A194734; |r|=(1+sqrt(5))/2
A054072, A194735, A194736, A194737; |r|=sqrt(2)
A194738, A194739, A194740, A194741; |r|=sqrt(3)
A194742, A194743, A194744, A194745; |r|=sqrt(5)
A194746, A194747, A194748, A194749; |r|=sqrt(6)
A194762, A194763, A194764, A194765; |r|=2^(1/3)
In each case, trivially, the sum of the first two sequences is A000027(for n>0), and likewise for the sum of the other two.

Examples

			{r}=0.7...; {2r}=0.4...; {3r}=0.1...;
{4f}=0.9...; {5r}=0.6...; so that a(5)=3.
		

Crossrefs

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 *)