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.

A292965 Rectangular array by antidiagonals: T(n,m) = rank of n*(Pi + m) when all the numbers k*(Pi+h), for k >= 1, h >= 0, are jointly ranked.

Original entry on oeis.org

1, 2, 5, 3, 8, 10, 4, 12, 16, 17, 6, 15, 22, 26, 23, 7, 20, 30, 35, 36, 31, 9, 25, 38, 46, 50, 47, 39, 11, 29, 45, 58, 64, 65, 59, 48, 13, 34, 54, 70, 78, 84, 79, 71, 56, 14, 41, 63, 83, 95, 103, 104, 97, 86, 67, 18, 44, 73, 94, 113, 123, 127, 124, 115, 99
Offset: 1

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Author

Clark Kimberling, Oct 06 2017

Keywords

Comments

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

Crossrefs

Cf. A182801.

Programs

  • Mathematica
    r = Pi; 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]  (* A292965 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A292965 sequence *)

Formula

T(n,m) = Sum_{k=1...[n + m*n/Pi]} [1 - Pi + n*(Pi + m)/k], where [ ]=floor.
Northwest corner:
1 2 3 4 6 7
5 8 12 15 20 25
10 16 22 30 38 45
17 26 35 46 58 70
23 36 50 64 78 95
31 47 65 84 103 123
39 59 79 104 127 153
The numbers k*(Pi+h), approximately:
(for k=1): 3.141 4.141 5.141 ...
(for k=2): 6.283 8.283 10.283 ...
(for k=3): 9.424 12.424 15.424 ...
Replacing each by its rank gives
1 2 3
5 8 12
10 16 22