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 | 1 |
| 3 | 6 |
| 4 | 51 |
| 5 | 555 |
| 6 | 205 |
| 7 | 805 |
| 8 | 58345 |
| 9 | 1197945 |
| 10 | 1374345 |
| 11 | 17425485 |
| 12 | 322622685 |
| 13 | 9738413685 |
| 14 | 11337871545 |
| 15 | 3308059755 |
| 16 | 990466892415 |
| 17 | 39460313827935 |
| 18 | 15438480702645 |
| 19 | 344802363740835 |
| 20 | 1298715036217599 |
| 21 | 60019600489849 |
| 22 | 1203757572990973 |