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.

A228020 Composite numbers whose initial, all intermediate and final iterated digit sums are composite numbers.

Table of values

n a(n)
1 4
2 6
3 8
4 9
5 15
6 18
7 22
8 24
9 26
10 27
11 33
12 35
13 36
14 40
15 42
16 44
17 45
18 51
19 54
20 60
21 62
22 63
23 69
24 72
25 78
26 80
27 81
28 87
29 90
30 96
31 99
32 105
33 108
34 112
35 114
36 116
37 117
38 121
39 123
40 125
41 126
42 130
43 132
44 134
45 135
46 141
47 143
48 144
49 150
50 152
51 153
52 159
53 161
54 162
55 168
56 170
57 171
58 177
59 180
60 186
61 189
62 195
63 198
64 202
65 204
66 206

List of values

[4, 6, 8, 9, 15, 18, 22, 24, 26, 27, 33, 35, 36, 40, 42, 44, 45, 51, 54, 60, 62, 63, 69, 72, 78, 80, 81, 87, 90, 96, 99, 105, 108, 112, 114, 116, 117, 121, 123, 125, 126, 130, 132, 134, 135, 141, 143, 144, 150, 152, 153, 159, 161, 162, 168, 170, 171, 177, 180, 186, 189, 195, 198, 202, 204, 206]