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 | 1 |
| 2 | 5 |
| 3 | 35 |
| 4 | 135 |
| 5 | 1755 |
| 6 | 6303 |
| 7 | 39815 |
| 8 | 132675 |
| 9 | 3322515 |
| 10 | 10561455 |
| 11 | 64566253 |
| 12 | 199681945 |
| 13 | 2391238415 |
| 14 | 7233344915 |