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) |
|---|---|
| 2 | 1 |
| 3 | 8 |
| 4 | 58 |
| 5 | 272 |
| 6 | 1770 |
| 7 | 7428 |
| 8 | 46928 |
| 9 | 189808 |
| 10 | 1185645 |
| 11 | 4724160 |
| 12 | 29362806 |
| 13 | 116207424 |
| 14 | 720606705 |
| 15 | 2842936320 |
| 16 | 17610412600 |
| 17 | 69378730880 |
| 18 | 429579843435 |
| 19 | 1691519468760 |
| 20 | 10472653252550 |
| 21 | 41235710124400 |
| 22 | 255326054688320 |
| 23 | 1005560117623204 |
| 24 | 6227515552731528 |
| 25 | 24534901740913872 |