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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.

A126223 Number of level steps in all 2-Motzkin paths (i.e., Motzkin paths with blue and red level steps) of length n, without red level steps on the x-axis.

Table of values

n a(n)
0 0
1 1
2 2
3 7
4 26
5 98
6 372
7 1419
8 5434
9 20878
10 80444
11 310726
12 1202852
13 4665412
14 18126760
15 70538355
16 274877370
17 1072515990
18 4189573740
19 16383007410
20 64126407180
21 251226790620
22 985033185240
23 3865138313790
24 15176957307876
25 59633260964748
26 234453859803352

List of values

[0, 1, 2, 7, 26, 98, 372, 1419, 5434, 20878, 80444, 310726, 1202852, 4665412, 18126760, 70538355, 274877370, 1072515990, 4189573740, 16383007410, 64126407180, 251226790620, 985033185240, 3865138313790, 15176957307876, 59633260964748, 234453859803352]

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

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