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 | 4 |
| 2 | 10 |
| 3 | 29 |
| 4 | 96 |
| 5 | 349 |
| 6 | 1350 |
| 7 | 5425 |
| 8 | 22297 |
| 9 | 92841 |
| 10 | 389456 |
| 11 | 1640630 |
| 12 | 6927937 |
| 13 | 29294645 |
| 14 | 123967625 |
| 15 | 524830618 |
| 16 | 2222483751 |
| 17 | 9412820990 |
| 18 | 39869076285 |
| 19 | 168877805414 |
| 20 | 715352976032 |
| 21 | 3030223762722 |
| 22 | 12836088840031 |
| 23 | 54374194848619 |