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 | 1 |
| 2 | 10 |
| 3 | 630 |
| 4 | 16290 |
| 5 | 52650 |
| 6 | 165600 |
| 7 | 986310 |
| 8 | 3428271 |
| 9 | 9446031 |
| 10 | 9485190 |
| 11 | 10693000 |
| 12 | 23698170 |
| 13 | 52168005 |
| 14 | 1270004401 |
| 15 | 2597150556 |
| 16 | 3484079550 |
| 17 | 14214075921 |
| 18 | 140884670790 |
| 19 | 217958758920 |
| 20 | 238847271435 |
| 21 | 403146774891 |