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.

A194836 Rectangular array, by antidiagonals: row n gives the positions of n in the fractal sequence A194835; an interspersion.

Original entry on oeis.org

1, 3, 2, 5, 4, 6, 9, 7, 10, 8, 13, 11, 14, 12, 15, 19, 16, 20, 17, 21, 18, 26, 23, 27, 24, 28, 25, 22, 33, 30, 35, 31, 36, 32, 29, 34, 42, 38, 44, 40, 45, 41, 37, 43, 39, 51, 47, 53, 49, 55, 50, 46, 52, 48, 54, 62, 57, 64, 59, 66, 61, 56, 63, 58, 65, 60, 74, 69, 76
Offset: 1

Views

Author

Clark Kimberling, Sep 03 2011

Keywords

Comments

Each pair of rows eventually intersperse.

Examples

			 Northwest corner:
1...3...5...9...13..19..26
2...4...7...11..16..23..30
6...10..14..20..27..35..44
8...12..17..24..31..40..49
15..21..28..36..45..55..66
18..25..32..41..50..61..73
		

Crossrefs

Programs

  • Mathematica
    r = -Sqrt[2];
    t[n_] := Table[FractionalPart[k*r], {k, 1, n}];
    f = Flatten[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 20}]]  (* A194835 *)
    TableForm[Table[Flatten[(Position[t[n], #1] &) /@ Sort[t[n], Less]], {n, 1, 15}]]
    row[n_] := Position[f, n];
    u = TableForm[Table[row[n], {n, 1, 20}]]
    g[n_, k_] := Part[row[n], k];
    p = Flatten[Table[g[k, n - k + 1], {n, 1, 13},
     {k, 1, n}]] (* A194836 *)
    q[n_] := Position[p, n]; Flatten[Table[q[n],
     {n, 1, 80}]]  (* A194837 *)