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 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 55 |
| 6 | 222 |
| 7 | 950 |
| 8 | 4265 |
| 9 | 19591 |
| 10 | 91678 |
| 11 | 434005 |
| 12 | 2073783 |
| 13 | 9979772 |
| 14 | 48315186 |
| 15 | 235088794 |
| 16 | 1148891118 |
| 17 | 5636168859 |
| 18 | 27743309673 |