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.

A222770 Number of 2Xn 0..1 arrays with exactly floor(2Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..1 order.

Table of values

n a(n)
1 0
2 3
3 4
4 11
5 18
6 73
7 152
8 470
9 1022
10 3361
11 7840
12 23386
13 57626
14 172387
15 434280
16 1257025
17 3275034
18 9399647
19 24776572
20 70325187
21 188540168
22 531573662
23 1436226680
24 4032772569
25 10987025446
26 30742228871
27 84180549328
28 235159618106

List of values

[0, 3, 4, 11, 18, 73, 152, 470, 1022, 3361, 7840, 23386, 57626, 172387, 434280, 1257025, 3275034, 9399647, 24776572, 70325187, 188540168, 531573662, 1436226680, 4032772569, 10987025446, 30742228871, 84180549328, 235159618106]

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

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