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 | 3 |
| 3 | 15 |
| 4 | 102 |
| 5 | 860 |
| 6 | 8548 |
| 7 | 97094 |
| 8 | 1234324 |
| 9 | 17302880 |
| 10 | 264503376 |
| 11 | 4371376170 |
| 12 | 77567318328 |
| 13 | 1469440535360 |
| 14 | 29578625457508 |
| 15 | 630090773216810 |
| 16 | 14155112389880376 |
| 17 | 334337856517696916 |
| 18 | 8280411098557369468 |