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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 19 |
| 5 | 63 |
| 6 | 216 |
| 7 | 760 |
| 8 | 2723 |
| 9 | 9880 |
| 10 | 36168 |
| 11 | 133237 |
| 12 | 492993 |
| 13 | 1829670 |
| 14 | 6804267 |
| 15 | 25336611 |
| 16 | 94416842 |
| 17 | 351989967 |
| 18 | 1312471879 |
| 19 | 4894023222 |
| 20 | 18248301701 |
| 21 | 68036380665 |
| 22 | 253638655582 |
| 23 | 945464013411 |
| 24 | 3523978989671 |
| 25 | 13133649924269 |