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.

A302157 Number of n X n 0..1 arrays with every element equal to 0, 1 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

Table of values

n a(n)
1 1
2 3
3 7
4 29
5 140
6 635
7 2853
8 19993
9 75825
10 786161
11 2915241
12 49663915
13 152854596
14 4893607560
15 13149908952
16 764803558904
17 1748158857032
18 193883417013099
19 378301363005384
20 78801036106269590
21 130887347815375440

List of values

[1, 3, 7, 29, 140, 635, 2853, 19993, 75825, 786161, 2915241, 49663915, 152854596, 4893607560, 13149908952, 764803558904, 1748158857032, 193883417013099, 378301363005384, 78801036106269590, 130887347815375440]

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

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