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 | 0 |
| 1 | 1 |
| 2 | 528 |
| 3 | 19764 |
| 4 | 270592 |
| 5 | 1953750 |
| 6 | 10435392 |
| 7 | 40356008 |
| 8 | 138547200 |
| 9 | 389021373 |
| 10 | 1031580000 |
| 11 | 2357962332 |
| 12 | 5347980288 |
| 13 | 10604527934 |
| 14 | 21307972224 |
| 15 | 38613915000 |
| 16 | 70936231936 |
| 17 | 118587960018 |
| 18 | 205403284944 |
| 19 | 322687828100 |
| 20 | 528669120000 |
| 21 | 797596142112 |
| 22 | 1245004111296 |
| 23 | 1801152941304 |
| 24 | 2738246860800 |