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 | 0 |
| 2 | 0 |
| 3 | 1640 |
| 4 | 119574 |
| 5 | 1497600 |
| 6 | 16733184 |
| 7 | 108081792 |
| 8 | 588805308 |
| 9 | 2544826368 |
| 10 | 9516533760 |
| 11 | 31328289720 |
| 12 | 92876121704 |
| 13 | 252846217728 |
| 14 | 638250227712 |
| 15 | 1511780699520 |
| 16 | 3387237774102 |
| 17 | 7228330481664 |