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 | 5 |
| 2 | 35 |
| 3 | 280 |
| 4 | 3080 |
| 5 | 46200 |
| 6 | 1016400 |
| 7 | 33541200 |
| 8 | 1710601200 |
| 9 | 136848096000 |
| 10 | 17379708192000 |
| 11 | 3528080762976000 |
| 12 | 1150154328730176000 |
| 13 | 603831022583342400000 |
| 14 | 511444876128091012800000 |
| 15 | 699656590543228505510400000 |
| 16 | 1546940721691078225683494400000 |