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.

A280569 a(n) = (-1)^n * 2 if n = 5*k and n!=0, otherwise a(n) = (-1)^n.

Table of values

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

List of values

[1, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1, -2, 1, -1, 1, -1, 2, -1, 1, -1, 1]