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 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 55 |
| 6 | 221 |
| 7 | 947 |
| 8 | 4239 |
| 9 | 19452 |
| 10 | 90791 |
| 11 | 428839 |
| 12 | 2043548 |
| 13 | 9807941 |