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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.

A278727 T(n,k)=Number of nXk 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order.

Table of values

n a(n)
1 4
2 10
3 10
4 20
5 60
6 20
7 35
8 275
9 275
10 35
11 56
12 1050
13 3232
14 1050
15 56
16 84
17 3492
18 33466
19 33466
20 3492
21 84
22 120
23 10401
24 306070
25 1058494
26 306070
27 10401
28 120
29 165
30 28288
31 2487889
32 30942600
33 30942600
34 2487889
35 28288
36 165
37 220
38 71266
39 18151220
40 815294800

List of values

[4, 10, 10, 20, 60, 20, 35, 275, 275, 35, 56, 1050, 3232, 1050, 56, 84, 3492, 33466, 33466, 3492, 84, 120, 10401, 306070, 1058494, 306070, 10401, 120, 165, 28288, 2487889, 30942600, 30942600, 2487889, 28288, 165, 220, 71266, 18151220, 815294800]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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