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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 12 |
| 6 | 40 |
| 7 | 153 |
| 8 | 638 |
| 9 | 2825 |
| 10 | 12938 |
| 11 | 60458 |
| 12 | 285664 |
| 13 | 1358283 |
| 14 | 6480694 |
| 15 | 30979999 |
| 16 | 148249768 |
| 17 | 709832688 |
| 18 | 3399805736 |
| 19 | 16286469156 |
| 20 | 78026226228 |
| 21 | 373832145200 |
| 22 | 1791120945112 |