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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.

A185405 1/7 the number of n X 2 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Table of values

n a(n)
1 1
2 13
3 150
4 1848
5 22656
6 278832
7 3430776
8 42221928
9 519611520
10 6394769688
11 78699293256
12 968538893952
13 11919644165496
14 146693048343528
15 1805326578739200
16 22217849450044248
17 273431322619829256

List of values

[1, 13, 150, 1848, 22656, 278832, 3430776, 42221928, 519611520, 6394769688, 78699293256, 968538893952, 11919644165496, 146693048343528, 1805326578739200, 22217849450044248, 273431322619829256]

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

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