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.

A020331 Numbers whose base-3 representation is the juxtaposition of two identical strings.

Table of values

n a(n)
1 4
2 8
3 30
4 40
5 50
6 60
7 70
8 80
9 252
10 280
11 308
12 336
13 364
14 392
15 420
16 448
17 476
18 504
19 532
20 560
21 588
22 616
23 644
24 672
25 700
26 728
27 2214
28 2296
29 2378
30 2460
31 2542
32 2624
33 2706
34 2788
35 2870
36 2952
37 3034
38 3116
39 3198
40 3280
41 3362
42 3444
43 3526
44 3608
45 3690
46 3772
47 3854
48 3936
49 4018

List of values

[4, 8, 30, 40, 50, 60, 70, 80, 252, 280, 308, 336, 364, 392, 420, 448, 476, 504, 532, 560, 588, 616, 644, 672, 700, 728, 2214, 2296, 2378, 2460, 2542, 2624, 2706, 2788, 2870, 2952, 3034, 3116, 3198, 3280, 3362, 3444, 3526, 3608, 3690, 3772, 3854, 3936, 4018]