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.

A252869 Number of n X n nonnegative integer arrays with upper left 0 and lower right 2n-4 and value increasing by 0 or 1 with every step right or down.

Table of values

n a(n)
1 0
2 1
3 44
4 615
5 7313
6 85801
7 1030330
8 12742873
9 161937617
10 2105918045
11 27918122131
12 376111502977
13 5136280530303
14 70961632168027
15 990271171218092
16 13940676224604419
17 197768060575469207
18 2824828302263709187
19 40595088350375470407
20 586585037283553891311

List of values

[0, 1, 44, 615, 7313, 85801, 1030330, 12742873, 161937617, 2105918045, 27918122131, 376111502977, 5136280530303, 70961632168027, 990271171218092, 13940676224604419, 197768060575469207, 2824828302263709187, 40595088350375470407, 586585037283553891311]

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

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