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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 31 |
| 9 | 1382 |
| 10 | 35396 |
| 11 | 686044 |
| 12 | 11204160 |
| 13 | 163014240 |
| 14 | 2184175040 |
| 15 | 27534645760 |
| 16 | 331417960960 |
| 17 | 3848744330240 |
| 18 | 43455499573248 |
| 19 | 479802090507264 |