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.

A247749 Number T(n,k) of lattice paths from (0,0) to (n,0) that do not go below the x-axis or above the diagonal x=y, consist of steps u=(1,1), U=(1,3), H=(1,0), d=(1,-1) and D=(1,-3) for which the area below the path is k; triangle T(n,k), n>=0, read by rows.

Table of values

n a(n)
0 1
1 1
2 1
3 1
4 1
5 2
6 1
7 1
8 3
9 3
10 2
11 2
12 0
13 1
14 1
15 4
16 6
17 6
18 6
19 3
20 4
21 2
22 1
23 1
24 1
25 5
26 10
27 13
28 15
29 12
30 14
31 15
32 9
33 12
34 5
35 5
36 1
37 1
38 1
39 6
40 15
41 24
42 32
43 33
44 37
45 46
46 40
47 43
48 34
49 28
50 23
51 16
52 10
53 5
54 2
55 1
56 1
57 7
58 21
59 40
60 61
61 75
62 88
63 114
64 122
65 134
66 137
67 118
68 127
69 101
70 99
71 69
72 68
73 41
74 38
75 19
76 17
77 5
78 5
79 0
80 1

List of values

[1, 1, 1, 1, 1, 2, 1, 1, 3, 3, 2, 2, 0, 1, 1, 4, 6, 6, 6, 3, 4, 2, 1, 1, 1, 5, 10, 13, 15, 12, 14, 15, 9, 12, 5, 5, 1, 1, 1, 6, 15, 24, 32, 33, 37, 46, 40, 43, 34, 28, 23, 16, 10, 5, 2, 1, 1, 7, 21, 40, 61, 75, 88, 114, 122, 134, 137, 118, 127, 101, 99, 69, 68, 41, 38, 19, 17, 5, 5, 0, 1]