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 | 3 |
| 3 | 15 |
| 4 | 45 |
| 5 | 585 |
| 6 | 2295 |
| 7 | 11475 |
| 8 | 29835 |
| 9 | 72675 |
| 10 | 424575 |
| 11 | 7977165 |
| 12 | 28851975 |
| 13 | 29277885 |
| 14 | 39317175 |