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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.

A381981 Number of compositions of n avoiding the patterns (1,2,3) and (3,2,1).

Table of values

n a(n)
0 1
1 1
2 2
3 4
4 8
5 16
6 30
7 56
8 100
9 173
10 293
11 482
12 779
13 1232
14 1928
15 2972
16 4546
17 6894
18 10435
19 15705
20 23692
21 35679
22 53976
23 81760
24 124611
25 190404
26 292871
27 452070
28 702042
29 1094034
30 1713879
31 2693284
32 4250165
33 6724535
34 10673794
35 16977795
36 27070285
37 43232232
38 69167372

List of values

[1, 1, 2, 4, 8, 16, 30, 56, 100, 173, 293, 482, 779, 1232, 1928, 2972, 4546, 6894, 10435, 15705, 23692, 35679, 53976, 81760, 124611, 190404, 292871, 452070, 702042, 1094034, 1713879, 2693284, 4250165, 6724535, 10673794, 16977795, 27070285, 43232232, 69167372]

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

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