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.

A348956 a(0) = 1; a(n) = Sum_{d|n, d < n} (-1)^(n/d + 1) * a(d - 1).

Table of values

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

List of values

[1, 0, -1, 1, -1, 1, 0, 1, -2, 0, 0, 1, 0, 1, -1, -1, -3, 1, 3, 1, 1, 0, -1, 1, -2, 0, -1, -2, -1, 1, 3, 1, -2, 0, 2, 0, 2, 1, -4, 0, -1, 1, 1, 1, 0, -4, 0, 1, -6, 1, 2, -3, 0, 1, 5, 0, 0, 3, 0, 1, 3, 1, -4, -1, -3, 0, 3, 1, 3, -1, -1, 1, 0, 1, -3, -4, -4, 1, 5, 1, -4]