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 | 240 |
| 2 | 14520 |
| 3 | 400080 |
| 4 | 6447660 |
| 5 | 70006512 |
| 6 | 561075720 |
| 7 | 3536846160 |
| 8 | 18363363690 |
| 9 | 81289041680 |
| 10 | 315029394792 |
| 11 | 1091144804400 |
| 12 | 3433533723900 |
| 13 | 9946019437200 |
| 14 | 26808012135000 |
| 15 | 67830161708592 |
| 16 | 162298598439330 |
| 17 | 369504358622640 |
| 18 | 804648531335960 |
| 19 | 1683493452034320 |