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.

A221453 Number of 0..n arrays of length n with each element unequal to at least one neighbor, with new values introduced in 0..n order.

Table of values

n a(n)
1 0
2 1
3 2
4 7
5 25
6 102
7 456
8 2219
9 11640
10 65364
11 390646
12 2472719
13 16508791
14 115839661
15 851634863
16 6542134884
17 52384882759
18 436290809772
19 3772143122161
20 33797290492507
21 313304547351868
22 3000631062271288
23 29651208549845055

List of values

[0, 1, 2, 7, 25, 102, 456, 2219, 11640, 65364, 390646, 2472719, 16508791, 115839661, 851634863, 6542134884, 52384882759, 436290809772, 3772143122161, 33797290492507, 313304547351868, 3000631062271288, 29651208549845055]

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

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