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.

A302213 Number of 3Xn 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 4
2 2
3 16
4 5
5 32
6 22
7 72
8 101
9 216
10 486
11 968
12 2541
13 5598
14 14718
15 35506
16 91947
17 231984
18 597758
19 1533828
20 3954067
21 10201602
22 26336704
23 68062810
24 175893407
25 454813604
26 1176002162
27 3041473404
28 7866219629
29 20346282584
30 52627527962
31 136129978706

List of values

[4, 2, 16, 5, 32, 22, 72, 101, 216, 486, 968, 2541, 5598, 14718, 35506, 91947, 231984, 597758, 1533828, 3954067, 10201602, 26336704, 68062810, 175893407, 454813604, 1176002162, 3041473404, 7866219629, 20346282584, 52627527962, 136129978706]