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.

Showing 1-3 of 3 results.

A259584 Numbers k such that [r[s*k]] - [s[r*k]] = -2, where r = sqrt(2), s=sqrt(3), and [ ] = floor.

Original entry on oeis.org

116, 314, 512, 657, 1340, 1422, 1620, 1818, 1900, 2161, 2243, 2441, 2639, 2982, 3124, 3322, 3747, 3800, 3945, 4027, 4143, 4225, 4766, 5251, 5449, 5531, 5729, 5927, 6125, 6270, 6352, 6953, 7091, 7233, 7431, 7711, 7774, 7856, 8054, 8252, 8457, 8595, 9278, 9360
Offset: 1

Views

Author

Clark Kimberling, Jul 15 2015

Keywords

Comments

It is easy to prove that [r[s*k]] - [s[r*k]] ranges from -2 to 2. For k = 1 to 10, the values of [r[s*k]] - [s[r*k]] are 0, 1, 1, 0, -1, 1, 1, -1, 1, 0.
The first -2 occurs when k = 116.

Crossrefs

Programs

  • Mathematica
    z = 12000; r = Sqrt[2]; s = Sqrt[3];
    u = Table[Floor[r*Floor[s*n]], {n, 1, z}];
    v = Table[Floor[s*Floor[r*n]], {n, 1, z}];
    Flatten[Position[u - v, -2]] (* A259584 *)
    Take[Flatten[Position[u - v, -1]], 100] (* A259585 *)
    Take[Flatten[Position[u - v, 0]], 100]  (* A259725 *)
    Take[Flatten[Position[u - v, 1]], 100]  (* A259587 *)
    Take[Flatten[Position[u - v, 2]], 100]  (* A259586 *)
    Select[Range[10000],Floor[Sqrt[2]Floor[Sqrt[3]#]]-Floor[Sqrt[3]Floor[ Sqrt[ 2]#]]==-2&] (* Harvey P. Dale, Dec 01 2016 *)

A259585 Numbers k such that [r[s*k]] - [s[r*k]] = -1, where r = sqrt(2), s=sqrt(3), and [ ] = floor.

Original entry on oeis.org

5, 8, 15, 29, 34, 39, 42, 45, 46, 49, 56, 58, 68, 71, 75, 87, 92, 95, 99, 102, 105, 109, 112, 121, 124, 127, 128, 131, 145, 150, 157, 162, 169, 174, 177, 184, 187, 191, 198, 203, 206, 213, 232, 237, 240, 243, 244, 247, 254, 256, 266, 269, 273, 285, 290, 295
Offset: 1

Views

Author

Clark Kimberling, Jul 15 2015

Keywords

Comments

It is easy to prove that [r[s*k]] - [s[r*k]] ranges from -2 to 2.

Examples

			For k = 1 to 10, the values of [r[s*k]] - [s[r*k]] are 0, 1, 1, 0, -1, 1, 1, -1, 1, 0, so that a(1) = 5.
		

Crossrefs

Programs

  • Mathematica
    z = 12000; r = Sqrt[2]; s = Sqrt[3];
    u = Table[Floor[r*Floor[s*n]], {n, 1, z}];
    v = Table[Floor[s*Floor[r*n]], {n, 1, z}];
    Flatten[Position[u - v, -2]] (* A259584 *)
    Take[Flatten[Position[u - v, -1]], 100] (* A259585 *)
    Take[Flatten[Position[u - v, 0]], 100]  (* A259725 *)
    Take[Flatten[Position[u - v, 1]], 100]  (* A259587 *)
    Take[Flatten[Position[u - v, 2]], 100]  (* A259586 *)

A259586 Numbers k such that [r[s*k]] - [s[r*k]] = 2, where r = sqrt(2), s=sqrt(3), and [ ] = floor.

Original entry on oeis.org

41, 67, 70, 123, 130, 205, 212, 328, 350, 403, 410, 444, 526, 548, 555, 608, 671, 700, 724, 750, 753, 806, 869, 888, 898, 951, 1026, 1033, 1067, 1086, 1096, 1149, 1224, 1231, 1265, 1291, 1294, 1347, 1376, 1429, 1489, 1504, 1545, 1571, 1574, 1627, 1709, 1716
Offset: 1

Views

Author

Clark Kimberling, Jul 15 2015

Keywords

Comments

It is easy to prove that [r[s*k]] - [s[r*k]] ranges from -2 to 2. For k = 1 to 10, the values of [r[s*k]] - [s[r*k]] are 0, 1, 1, 0, -1, 1, 1, -1, 1, 0; the first appearance of 2 is when k = 41.

Crossrefs

Programs

  • Mathematica
    z = 12000; r = Sqrt[2]; s = Sqrt[3];
    u = Table[Floor[r*Floor[s*n]], {n, 1, z}];
    v = Table[Floor[s*Floor[r*n]], {n, 1, z}];
    Flatten[Position[u - v, -2]] (* A259584 *)
    Take[Flatten[Position[u - v, -1]], 100] (* A259585 *)
    Take[Flatten[Position[u - v, 0]], 100]  (* A259725 *)
    Take[Flatten[Position[u - v, 1]], 100]  (* A259587 *)
    Take[Flatten[Position[u - v, 2]], 100]  (* A259586 *)
    Select[Range[2000],Floor[Sqrt[2]Floor[Sqrt[3]#]]-Floor[Sqrt[3]Floor[Sqrt[2]#]]==2&] (* Harvey P. Dale, Aug 10 2024 *)
Showing 1-3 of 3 results.