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.

A059020 Number of 2 X n checkerboards (with at least one red square) in which the set of red squares is edge connected.

Table of values

n a(n)
0 0
1 3
2 13
3 40
4 108
5 275
6 681
7 1664
8 4040
9 9779
10 23637
11 57096
12 137876
13 332899
14 803729
15 1940416
16 4684624
17 11309731
18 27304157
19 65918120
20 159140476
21 384199155
22 927538873
23 2239276992
24 5406092952
25 13051462995
26 31509019045
27 76069501192
28 183648021540
29 443365544387

List of values

[0, 3, 13, 40, 108, 275, 681, 1664, 4040, 9779, 23637, 57096, 137876, 332899, 803729, 1940416, 4684624, 11309731, 27304157, 65918120, 159140476, 384199155, 927538873, 2239276992, 5406092952, 13051462995, 31509019045, 76069501192, 183648021540, 443365544387]

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

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