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.

A293056 Rectangular array by antidiagonals: T(n,m) = rank of n*log(2)+m when all the numbers k*log(2)+h, for k >= 1, h >= 0, are jointly ranked.

Original entry on oeis.org

1, 3, 2, 6, 5, 4, 11, 9, 8, 7, 17, 15, 13, 12, 10, 25, 22, 20, 18, 16, 14, 34, 31, 28, 26, 23, 21, 19, 45, 41, 38, 35, 32, 29, 27, 24, 57, 53, 49, 46, 42, 39, 36, 33, 30, 70, 66, 62, 58, 54, 50, 47, 43, 40, 37, 85, 80, 76, 72, 67, 63, 59, 55, 51, 48, 44, 101
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. As an array, this is the interspersion of 1/log(2); see A283962.

Examples

			Northwest corner:
1      3      6      11     17     25     34
2      5      9      15     22     31     41
4      8      13     20     28     38     49
7      12     18     26     35     46     58
10     16     23     32     42     54     67
14     21     29     39     50     63     77
19     27     36     47     59     73     88
24     33     43     55     68     83     99
30     40     51     64     78     94     111
The numbers k*r+h, approximately:
(for k=1):   0.693   1.693   2.693 ...
(for k=2):   1.386   2.386   3.386 ...
(for k=3):   2.079   3.079   4.079 ...
Replacing each k*r+h by its rank gives
1    3    6
2    5    9
4    8    13
		

Crossrefs

Cf. A283962.

Programs

  • Mathematica
    r = Log[2]; z = 12;
    t[n_, m_] := Sum[Floor[1 + m + (n - k) r], {k, 1, n + Floor[m/r]}];
    u = Table[t[n, m], {n, 1, z}, {m, 0, z}]
    Grid[u] (* A293056 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A293056 sequence *)

Formula

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