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.

A053727 Triangle T(n,k) = Sum_{d|gcd(n,k)} mu(d)*C(n/d,k/d) (n >= 1, 1 <= k <= n).

Table of values

n a(n)
1 1
2 2
3 0
4 3
5 3
6 0
7 4
8 4
9 4
10 0
11 5
12 10
13 10
14 5
15 0
16 6
17 12
18 18
19 12
20 6
21 0
22 7
23 21
24 35
25 35
26 21
27 7
28 0
29 8
30 24
31 56
32 64
33 56
34 24
35 8
36 0
37 9
38 36
39 81
40 126
41 126
42 81
43 36
44 9
45 0
46 10
47 40
48 120
49 200
50 250
51 200
52 120
53 40
54 10
55 0
56 11
57 55
58 165
59 330
60 462
61 462
62 330
63 165
64 55
65 11
66 0
67 12
68 60

List of values

[1, 2, 0, 3, 3, 0, 4, 4, 4, 0, 5, 10, 10, 5, 0, 6, 12, 18, 12, 6, 0, 7, 21, 35, 35, 21, 7, 0, 8, 24, 56, 64, 56, 24, 8, 0, 9, 36, 81, 126, 126, 81, 36, 9, 0, 10, 40, 120, 200, 250, 200, 120, 40, 10, 0, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 0, 12, 60]