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.

A281606 Number of 3Xn 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

Table of values

n a(n)
1 5
2 50
3 209
4 1283
5 8180
6 49572
7 302304
8 1849212
9 11295326
10 69003066
11 421598546
12 2575763454
13 15736620000
14 96143466614
15 587391366384
16 3588683849428
17 21925168436114
18 133952450888038
19 818386359248384
20 4999955088202190

List of values

[5, 50, 209, 1283, 8180, 49572, 302304, 1849212, 11295326, 69003066, 421598546, 2575763454, 15736620000, 96143466614, 587391366384, 3588683849428, 21925168436114, 133952450888038, 818386359248384, 4999955088202190]

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

Content is available under The OEIS End-User License Agreement.