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.

A268735 Number of n X 3 binary arrays with some 1 horizontally or vertically adjacent to some other 1 exactly once.

Table of values

n a(n)
1 2
2 15
3 80
4 396
5 1788
6 7831
7 33170
8 137868
9 563486
10 2275119
11 9091772
12 36031648
13 141793168
14 554669335
15 2158604934
16 8363066408
17 32273565050
18 124112115647
19 475807505288
20 1819019281732
21 6936664653476
22 26392068734023
23 100206016839642

List of values

[2, 15, 80, 396, 1788, 7831, 33170, 137868, 563486, 2275119, 9091772, 36031648, 141793168, 554669335, 2158604934, 8363066408, 32273565050, 124112115647, 475807505288, 1819019281732, 6936664653476, 26392068734023, 100206016839642]

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

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