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 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 51 |
| 6 | 217 |
| 7 | 912 |
| 8 | 3785 |
| 9 | 15554 |
| 10 | 63458 |
| 11 | 257566 |
| 12 | 1041548 |
| 13 | 4200462 |
| 14 | 16906262 |
| 15 | 67943341 |
| 16 | 272740788 |
| 17 | 1093881967 |
| 18 | 4384217569 |
| 19 | 17562176283 |
| 20 | 70319782015 |
| 21 | 281466691159 |
| 22 | 1126304935761 |
| 23 | 4505961410365 |
| 24 | 18023526090613 |
| 25 | 72082118816829 |
| 26 | 288245594631227 |
| 27 | 1152536796877409 |
| 28 | 4607992736095739 |
| 29 | 18422141293792669 |
| 30 | 73645313049839723 |