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 | 17 |
| 7 | 496 |
| 8 | 8576 |
| 9 | 115072 |
| 10 | 1328336 |
| 11 | 13899904 |
| 12 | 135927040 |
| 13 | 1266360320 |
| 14 | 11385790720 |
| 15 | 99682672640 |
| 16 | 855303553024 |
| 17 | 7226263666688 |
| 18 | 60329459699712 |
| 19 | 499027284295680 |