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.

A284432 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1 and a minimal sum (= A282168(n)).

Table of values

n a(n)
1 1
2 1
3 2
4 2
5 4
6 4
7 4
8 48
9 48
10 144
11 144
12 144
13 2160
14 8496
15 21312
16 110592
17 203904
18 407808
19 815616
20 1631232
21 15667200
22 31334400
23 445114368
24 890228736
25 7291772928
26 14583545856
27 36458864640
28 72917729280
29 145835458560
30 1694545920000
31 16054441574400
32 101226251059200
33 421941436416000
34 2144473989120000
35 13603849760931840

List of values

[1, 1, 2, 2, 4, 4, 4, 48, 48, 144, 144, 144, 2160, 8496, 21312, 110592, 203904, 407808, 815616, 1631232, 15667200, 31334400, 445114368, 890228736, 7291772928, 14583545856, 36458864640, 72917729280, 145835458560, 1694545920000, 16054441574400, 101226251059200, 421941436416000, 2144473989120000, 13603849760931840]

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

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