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.

A284431 The number of positive integer sequences of length n with no duplicate substrings of length greater than 1, every number different from its neighbors, and a minimal sum (= A282166(n)).

Table of values

n a(n)
1 1
2 2
3 1
4 6
5 2
6 42
7 12
8 116
9 18
10 84
11 168
12 336
13 384
14 6864
15 7872
16 67392
17 52800
18 357120
19 115200
20 748800
21 3093120
22 11681280
23 26853120
24 43130880
25 74649600
26 2238382080
27 3588157440
28 51775856640
29 63188398080
30 653811056640
31 480220876800
32 4284050964480
33 1316818944000
34 11061279129600
35 76921038028800

List of values

[1, 2, 1, 6, 2, 42, 12, 116, 18, 84, 168, 336, 384, 6864, 7872, 67392, 52800, 357120, 115200, 748800, 3093120, 11681280, 26853120, 43130880, 74649600, 2238382080, 3588157440, 51775856640, 63188398080, 653811056640, 480220876800, 4284050964480, 1316818944000, 11061279129600, 76921038028800]

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

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