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.

A201534 Number of nX3 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.

Table of values

n a(n)
1 3
2 25
3 111
4 633
5 3354
6 16393
7 72811
8 293831
9 1087857
10 3735546
11 12012530
12 36466979
13 105202136
14 289996482
15 767360174
16 1956720113
17 4824093641
18 11531663892
19 26793101230
20 60636948110
21 133921364986
22 289121431541
23 611037886807

List of values

[3, 25, 111, 633, 3354, 16393, 72811, 293831, 1087857, 3735546, 12012530, 36466979, 105202136, 289996482, 767360174, 1956720113, 4824093641, 11531663892, 26793101230, 60636948110, 133921364986, 289121431541, 611037886807]

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

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