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.

A207428 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically.

Table of values

n a(n)
1 9
2 81
3 351
4 1521
5 8463
6 47089
7 241087
8 1234321
9 6520459
10 34445161
11 179832029
12 938870881
13 4924284469
14 25827382681
15 135217499129
16 707921987161
17 3708936179293
18 19431812871409
19 101777874172609
20 533081279633809

List of values

[9, 81, 351, 1521, 8463, 47089, 241087, 1234321, 6520459, 34445161, 179832029, 938870881, 4924284469, 25827382681, 135217499129, 707921987161, 3708936179293, 19431812871409, 101777874172609, 533081279633809]

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

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