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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.

A329671 Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH and DD.

Table of values

n a(n)
0 1
1 1
2 1
3 3
4 4
5 6
6 12
7 20
8 33
9 61
10 109
11 191
12 349
13 639
14 1159
15 2133
16 3953
17 7311
18 13595
19 25417
20 47570
21 89272
22 168126
23 317226
24 599699
25 1136403
26 2157363
27 4102113
28 7813560
29 14906230
30 28476388
31 54475340
32 104347011
33 200113007
34 384207955
35 738468129
36 1420824404
37 2736345674
38 5274795212

List of values

[1, 1, 1, 3, 4, 6, 12, 20, 33, 61, 109, 191, 349, 639, 1159, 2133, 3953, 7311, 13595, 25417, 47570, 89272, 168126, 317226, 599699, 1136403, 2157363, 4102113, 7813560, 14906230, 28476388, 54475340, 104347011, 200113007, 384207955, 738468129, 1420824404, 2736345674, 5274795212]

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

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