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.

A207560 Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically.

Table of values

n a(n)
1 9
2 81
3 241
4 636
5 2135
6 6709
7 23276
8 78733
9 277781
10 973608
11 3477827
12 12422849
13 44780404
14 161681185
15 586480585
16 2130883040
17 7761845079
18 28308582237
19 103395253764
20 377977638085
21 1382951559309
22 5062965194920
23 18545296800603

List of values

[9, 81, 241, 636, 2135, 6709, 23276, 78733, 277781, 973608, 3477827, 12422849, 44780404, 161681185, 586480585, 2130883040, 7761845079, 28308582237, 103395253764, 377977638085, 1382951559309, 5062965194920, 18545296800603]

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

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