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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.

A304361 Number of Dyck paths of semilength 2n having exactly n (possibly overlapping) occurrences of the consecutive pattern UDUD, where U=(1,1) and D=(1,-1).

Table of values

n a(n)
0 1
1 1
2 1
3 9
4 41
5 244
6 1555
7 10037
8 68599
9 476981
10 3399518
11 24652718
12 181411439
13 1352123760
14 10185964435
15 77458698781
16 593871350009
17 4586247704944
18 35646681303447
19 278665636846853
20 2189789189667782
21 17288684906561300
22 137081212514315262
23 1091163063187762414

List of values

[1, 1, 1, 9, 41, 244, 1555, 10037, 68599, 476981, 3399518, 24652718, 181411439, 1352123760, 10185964435, 77458698781, 593871350009, 4586247704944, 35646681303447, 278665636846853, 2189789189667782, 17288684906561300, 137081212514315262, 1091163063187762414]

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

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