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 | 220 |
| 4 | 715 |
| 5 | 16016 |
| 6 | 180180 |
| 7 | 2619760 |
| 8 | 39503750 |
| 9 | 642172960 |
| 10 | 11111964864 |
| 11 | 204016477080 |
| 12 | 3959206825210 |
| 13 | 80952590044480 |
| 14 | 1739019535313720 |
| 15 | 39150661649469744 |
| 16 | 921633956154372175 |
| 17 | 22640304292494917600 |