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 | 3 |
| 4 | 9 |
| 5 | 29 |
| 6 | 91 |
| 7 | 322 |
| 8 | 1206 |
| 9 | 4600 |
| 10 | 17931 |
| 11 | 70577 |
| 12 | 279652 |
| 13 | 1110758 |
| 14 | 4424120 |
| 15 | 17647314 |
| 16 | 70484576 |
| 17 | 281750598 |
| 18 | 1127181327 |