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.

A119331 Number triangle T(n,k)=sum{i=0..n, (-1)^(n-i)*C(n,i)*sum{j=0..i-k, C(k,2j)*C(i-k,2j)*2^j}}.

Table of values

n a(n)
0 1
1 0
2 1
3 0
4 -1
5 1
6 0
7 1
8 -2
9 1
10 0
11 -1
12 5
13 -3
14 1
15 0
16 1
17 -8
18 12
19 -4
20 1
21 0
22 -1
23 11
24 -28
25 22
26 -5
27 1
28 0
29 1
30 -14
31 51
32 -68
33 35
34 -6
35 1
36 0
37 -1
38 17
39 -81
40 159
41 -135
42 51
43 -7
44 1
45 0
46 1
47 -20
48 118
49 -312
50 390
51 -236
52 70
53 -8
54 1
55 0
56 -1
57 23
58 -162
59 544
60 -926
61 816
62 -378
63 92
64 -9
65 1

List of values

[1, 0, 1, 0, -1, 1, 0, 1, -2, 1, 0, -1, 5, -3, 1, 0, 1, -8, 12, -4, 1, 0, -1, 11, -28, 22, -5, 1, 0, 1, -14, 51, -68, 35, -6, 1, 0, -1, 17, -81, 159, -135, 51, -7, 1, 0, 1, -20, 118, -312, 390, -236, 70, -8, 1, 0, -1, 23, -162, 544, -926, 816, -378, 92, -9, 1]