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 | 6 |
| 2 | 36 |
| 3 | 90 |
| 4 | 330 |
| 5 | 1008 |
| 6 | 3354 |
| 7 | 10710 |
| 8 | 34884 |
| 9 | 112530 |
| 10 | 364722 |
| 11 | 1179360 |
| 12 | 3817938 |
| 13 | 12352782 |
| 14 | 39978180 |
| 15 | 129366090 |
| 16 | 418647162 |
| 17 | 1354755024 |
| 18 | 4384104618 |
| 19 | 14187219750 |
| 20 | 45910873476 |
| 21 | 148570600866 |
| 22 | 480784736226 |
| 23 | 1555851810240 |
| 24 | 5034842671650 |