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.

A217540 Scambler statistic on Dyck paths. Triangle T(n, k) read by rows, n >= 0, -n <= k <= n, T(n, k) is the number of Dyck paths of semilength n and k = number of returns + number of hills - number of peaks.

Table of values

n a(n)
0 1
1 0
2 0
3 1
4 0
5 0
6 1
7 0
8 1
9 0
10 0
11 1
12 1
13 2
14 0
15 1
16 0
17 0
18 1
19 3
20 4
21 2
22 3
23 0
24 1
25 0
26 0
27 1
28 6
29 10
30 9
31 8
32 3
33 4
34 0
35 1
36 0
37 0
38 1
39 10
40 25
41 30
42 26
43 17
44 13
45 4
46 5
47 0
48 1
49 0
50 0
51 1
52 15
53 56
54 90
55 90
56 70
57 49
58 27
59 19
60 5
61 6
62 0
63 1
64 0
65 0
66 1
67 21
68 112
69 245
70 301
71 266
72 197
73 128
74 80
75 39
76 26
77 6
78 7
79 0
80 1

List of values

[1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 2, 0, 1, 0, 0, 1, 3, 4, 2, 3, 0, 1, 0, 0, 1, 6, 10, 9, 8, 3, 4, 0, 1, 0, 0, 1, 10, 25, 30, 26, 17, 13, 4, 5, 0, 1, 0, 0, 1, 15, 56, 90, 90, 70, 49, 27, 19, 5, 6, 0, 1, 0, 0, 1, 21, 112, 245, 301, 266, 197, 128, 80, 39, 26, 6, 7, 0, 1]