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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 90 |
| 6 | 393 |
| 7 | 1769 |
| 8 | 7957 |
| 9 | 35133 |
| 10 | 151675 |
| 11 | 642695 |
| 12 | 2689411 |
| 13 | 11176469 |
| 14 | 46313531 |
| 15 | 191837707 |
| 16 | 795251170 |
| 17 | 3300506324 |
| 18 | 13712825121 |
| 19 | 57019988099 |
| 20 | 237221971144 |
| 21 | 987206194720 |
| 22 | 4108816936769 |
| 23 | 17101813661923 |
| 24 | 71181293634767 |