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) |
|---|---|
| 5 | 280 |
| 6 | 6240 |
| 7 | 75600 |
| 8 | 954240 |
| 9 | 12579840 |
| 10 | 175392000 |
| 11 | 2594592000 |
| 12 | 40721049600 |
| 13 | 677053977600 |
| 14 | 11901451161600 |
| 15 | 220690229760000 |
| 16 | 4307253350400000 |
| 17 | 88289523818496000 |
| 18 | 1896762491559936000 |
| 19 | 42625344258072576000 |
| 20 | 1000193047805952000000 |
| 21 | 24463730767033958400000 |
| 22 | 622724156293184225280000 |