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.

A307156 Number triangle T(n,k) = Sum_{j=0..n-k} (-1)^j * binomial(k,3*j) * binomial(n-k,3*j).

Table of values

n a(n)
0 1
1 1
2 1
3 1
4 1
5 1
6 1
7 1
8 1
9 1
10 1
11 1
12 1
13 1
14 1
15 1
16 1
17 1
18 1
19 1
20 1
21 1
22 1
23 1
24 0
25 1
26 1
27 1
28 1
29 1
30 1
31 -3
32 -3
33 1
34 1
35 1
36 1
37 1
38 1
39 -9
40 -15
41 -9
42 1
43 1
44 1
45 1
46 1
47 1
48 -19
49 -39
50 -39
51 -19
52 1
53 1
54 1
55 1
56 1
57 1
58 -34
59 -79
60 -99
61 -79
62 -34
63 1
64 1
65 1
66 1
67 1
68 1
69 -55
70 -139
71 -199
72 -199
73 -139
74 -55
75 1
76 1
77 1

List of values

[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, -3, -3, 1, 1, 1, 1, 1, 1, -9, -15, -9, 1, 1, 1, 1, 1, 1, -19, -39, -39, -19, 1, 1, 1, 1, 1, 1, -34, -79, -99, -79, -34, 1, 1, 1, 1, 1, 1, -55, -139, -199, -199, -139, -55, 1, 1, 1]