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.

A009205 a(n) = gcd(d(n), sigma(n)).

Table of values

n a(n)
1 1
2 1
3 2
4 1
5 2
6 4
7 2
8 1
9 1
10 2
11 2
12 2
13 2
14 4
15 4
16 1
17 2
18 3
19 2
20 6
21 4
22 4
23 2
24 4
25 1
26 2
27 4
28 2
29 2
30 8
31 2
32 3
33 4
34 2
35 4
36 1
37 2
38 4
39 4
40 2
41 2
42 8
43 2
44 6
45 6
46 4
47 2
48 2
49 3
50 3
51 4
52 2
53 2
54 8
55 4
56 8
57 4
58 2
59 2
60 12
61 2
62 4
63 2
64 1
65 4
66 8
67 2
68 6
69 4
70 8
71 2
72 3
73 2
74 2
75 2
76 2
77 4
78 8
79 2
80 2
81 1
82 2
83 2
84 4
85 4
86 4
87 4
88 4
89 2
90 6
91 4
92 6
93 4
94 4
95 4
96 12
97 2
98 3
99 6
100 1
101 2
102 8
103 2
104 2
105 8
106 2
107 2
108 4
109 2
110 8
111 4
112 2
113 2
114 8
115 4
116 6
117 2
118 4
119 4
120 8

List of values

[1, 1, 2, 1, 2, 4, 2, 1, 1, 2, 2, 2, 2, 4, 4, 1, 2, 3, 2, 6, 4, 4, 2, 4, 1, 2, 4, 2, 2, 8, 2, 3, 4, 2, 4, 1, 2, 4, 4, 2, 2, 8, 2, 6, 6, 4, 2, 2, 3, 3, 4, 2, 2, 8, 4, 8, 4, 2, 2, 12, 2, 4, 2, 1, 4, 8, 2, 6, 4, 8, 2, 3, 2, 2, 2, 2, 4, 8, 2, 2, 1, 2, 2, 4, 4, 4, 4, 4, 2, 6, 4, 6, 4, 4, 4, 12, 2, 3, 6, 1, 2, 8, 2, 2, 8, 2, 2, 4, 2, 8, 4, 2, 2, 8, 4, 6, 2, 4, 4, 8]