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.

A114709 Triangle read by rows: T(n,k) is the number of hill-free Schroeder paths of length 2n that have k horizontal steps on the x-axis (0<=k<=n). A Schroeder path of length 2n is a lattice path from (0,0) to (2n,0) consisting of U=(1,1), D=(1,-1) and H=(2,0) steps and never going below the x-axis. A hill is a peak at height 1.

Table of values

n a(n)
0 1
1 0
2 1
3 2
4 0
5 1
6 6
7 4
8 0
9 1
10 26
11 12
12 6
13 0
14 1
15 114
16 56
17 18
18 8
19 0
20 1
21 526
22 252
23 90
24 24
25 10
26 0
27 1
28 2502
29 1192
30 414
31 128
32 30
33 12
34 0
35 1
36 12194
37 5772
38 2006
39 600
40 170
41 36
42 14
43 0
44 1
45 60570
46 28536
47 9882
48 2976
49 810
50 216
51 42
52 16
53 0
54 1
55 305526
56 143388
57 49554
58 14904
59 4110
60 1044

List of values

[1, 0, 1, 2, 0, 1, 6, 4, 0, 1, 26, 12, 6, 0, 1, 114, 56, 18, 8, 0, 1, 526, 252, 90, 24, 10, 0, 1, 2502, 1192, 414, 128, 30, 12, 0, 1, 12194, 5772, 2006, 600, 170, 36, 14, 0, 1, 60570, 28536, 9882, 2976, 810, 216, 42, 16, 0, 1, 305526, 143388, 49554, 14904, 4110, 1044]