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) |
|---|---|
| 1 | 10 |
| 2 | 120 |
| 3 | 1560 |
| 4 | 13440 |
| 5 | 226200 |
| 6 | 2021760 |
| 7 | 32518360 |
| 8 | 274391040 |
| 9 | 4534807680 |
| 10 | 51953616000 |
| 11 | 646094232960 |
| 12 | 4662793175040 |
| 13 | 97266341877120 |
| 14 | 1070382142166400 |
| 15 | 13666309113600000 |
| 16 | 109897747141754880 |
| 17 | 2016918439151095000 |
| 18 | 17518491733377024000 |
| 19 | 290436363064202660760 |