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.

A208638 Number of 3 X n 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors.

Table of values

n a(n)
1 4
2 13
3 32
4 71
5 150
6 309
7 628
8 1267
9 2546
10 5105
11 10224
12 20463
13 40942
14 81901
15 163820
16 327659
17 655338
18 1310697
19 2621416
20 5242855
21 10485734
22 20971493
23 41943012
24 83886051
25 167772130
26 335544289
27 671088608
28 1342177247
29 2684354526
30 5368709085

List of values

[4, 13, 32, 71, 150, 309, 628, 1267, 2546, 5105, 10224, 20463, 40942, 81901, 163820, 327659, 655338, 1310697, 2621416, 5242855, 10485734, 20971493, 41943012, 83886051, 167772130, 335544289, 671088608, 1342177247, 2684354526, 5368709085]

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

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