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.

A201270 Number of n X n 0..2 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other.

Table of values

n a(n)
0 1
1 3
2 5
3 7
4 85
5 556
6 1260
7 27008
8 215577
9 613916
10 16442049
11 152673459
12 487975060
13 14392411292
14 144918917509
15 496264541787
16 15559415313705
17 165127072154120
18 592098075114238
19 19339952787547252
20 212870280758956694
21 788675446037414831
22 26535438036570486429
23 300014957716483809886

List of values

[1, 3, 5, 7, 85, 556, 1260, 27008, 215577, 613916, 16442049, 152673459, 487975060, 14392411292, 144918917509, 496264541787, 15559415313705, 165127072154120, 592098075114238, 19339952787547252, 212870280758956694, 788675446037414831, 26535438036570486429, 300014957716483809886]

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

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