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.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 17 |
| 3 | 53 |
| 4 | 163 |
| 5 | 487 |
| 6 | 1459 |
| 7 | 4373 |
| 8 | 13121 |
| 9 | 39367 |
| 10 | 472391 |
| 11 | 1062881 |
| 12 | 1062881 |
| 13 | 19131877 |
| 14 | 19131877 |
| 15 | 57395627 |
| 16 | 86093443 |
| 17 | 258280327 |
| 18 | 3874204891 |
| 19 | 6973568801 |
| 20 | 6973568801 |
| 21 | 188286357653 |
| 22 | 188286357653 |
| 23 | 188286357653 |
| 24 | 4518872583697 |
| 25 | 15251194969973 |