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 | 12 |
| 4 | 96 |
| 5 | 3120 |
| 6 | 115200 |
| 7 | 5836320 |
| 8 | 382072320 |
| 9 | 31488549120 |
| 10 | 3191834419200 |
| 11 | 390445460697600 |
| 12 | 56729732529254400 |
| 13 | 9659308746908620800 |
| 14 | 1905270127543015833600 |
| 15 | 431026303509734220288000 |
| 16 | 110865322076320374571008000 |
| 17 | 32172949121885378686623744000 |