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.

A302208 Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

Table of values

n a(n)
1 1
2 13
3 5
4 7
5 18
6 55
7 172
8 575
9 1962
10 6756
11 23400
12 81288
13 283089
14 987275
15 3444621
16 12023434
17 41982749
18 146612525
19 512036344
20 1788383898
21 6246509941
22 21818284060
23 76209472929
24 266195826556
25 929812279542
26 3247807389634
27 11344517688838

List of values

[1, 13, 5, 7, 18, 55, 172, 575, 1962, 6756, 23400, 81288, 283089, 987275, 3444621, 12023434, 41982749, 146612525, 512036344, 1788383898, 6246509941, 21818284060, 76209472929, 266195826556, 929812279542, 3247807389634, 11344517688838]

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

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