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.

A292960 Rectangular array by antidiagonals: T(n,m) = rank of n*(r+m) when all the numbers k*(r+h), where r = ((1+sqrt(5))/2)^2, k>=1, h>=0, are jointly ranked.

Original entry on oeis.org

1, 2, 4, 3, 7, 9, 5, 11, 15, 13, 6, 16, 22, 23, 19, 8, 20, 29, 34, 32, 27, 10, 25, 38, 44, 47, 43, 33, 12, 30, 46, 57, 62, 61, 53, 40, 14, 36, 55, 69, 78, 81, 75, 66, 49, 17, 41, 65, 83, 95, 102, 100, 91, 76, 56, 18, 48, 74, 96, 112, 122, 124, 119, 107, 88
Offset: 1

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Author

Clark Kimberling, Oct 05 2017

Keywords

Comments

Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.

Examples

			Northwest corner:
1   2   3    5    6    8   10
4   7   11   16   20   25  30
9   15  22   29   38   46  55
13  23  34   44   57   69  83
19  32  47   62   78   95  112
27  43  61   81   102  122 145
The numbers k*(r+h), approximately:
(for k=1):   2.618   3.618   4.618 ...
(for k=2):   5.236   7.236   9.236 ...
(for k=3):   7.854   10.854   13.854 ...
Replacing each k*(r+h) by its rank gives
1    2     3
4    7     11
9    15    22
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 12;
    t[n_, m_] := Sum[Floor[1 - r + n*(r + m)/k], {k, 1, Floor[n + m*n/r]}];
    u = Table[t[n, m], {n, 1, z}, {m, 0, z}]; TableForm[u]  (* A292960 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A292960 sequence *)

Formula

T(n,m) = Sum_{k=1...[n + m*n/r]} [1 - r + n*(r + m)/k], where r=(GoldenRatio)^2 and [ ]=floor.