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 | 2 |
| 4 | 6 |
| 5 | 15 |
| 6 | 105 |
| 7 | 385 |
| 8 | 2310 |
| 9 | 6006 |
| 10 | 102102 |
| 11 | 277134 |
| 12 | 6374082 |
| 13 | 16804398 |
| 14 | 520936338 |
| 15 | 3038795305 |
| 16 | 66853496710 |
| 17 | 190275336790 |
| 18 | 7420738134810 |
| 19 | 17897074325130 |
| 20 | 769574195980590 |
| 21 | 1903683537425670 |
| 22 | 100895227483560510 |
| 23 | 258818192240437830 |
| 24 | 15787909726666707630 |
| 25 | 36475515575402393490 |