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 | 15 |
| 5 | 35 |
| 6 | 315 |
| 7 | 693 |
| 8 | 9009 |
| 9 | 19305 |
| 10 | 328185 |
| 11 | 692835 |
| 12 | 14549535 |
| 13 | 30421755 |
| 14 | 760543875 |
| 15 | 1579591125 |
| 16 | 45808142625 |
| 17 | 94670161425 |
| 18 | 3124115327025 |
| 19 | 6432002143875 |
| 20 | 237984079323375 |
| 21 | 488493636505875 |
| 22 | 20028239096740875 |