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.

A307776 a(1) = 1; a(n+1) = Sum_{d|n} (-1)^(n/d+1)*a(d).

Table of values

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

List of values

[1, 1, 0, 1, -1, 0, 0, 1, -2, -1, 0, 1, 0, 1, 1, 1, -3, -2, 0, 1, 2, 3, 3, 4, 1, 1, 1, 0, -2, -1, -2, -1, -6, -5, -2, -2, 2, 3, 3, 4, 3, 4, 3, 4, 0, -1, -4, -3, -11, -10, -11, -13, -15, -14, -15, -15, -18, -17, -15, -14, -11, -10, -8, -7, -11, -11, -2, -1, 6, 10, 13, 14, 21, 22, 20]