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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 13 |
| 5 | 60 |
| 6 | 225 |
| 7 | 1148 |
| 8 | 4235 |
| 9 | 22296 |
| 10 | 82425 |
| 11 | 440308 |
| 12 | 1634435 |
| 13 | 8809736 |
| 14 | 32819839 |
| 15 | 178029138 |
| 16 | 665162897 |
| 17 | 3625521728 |
| 18 | 13577768505 |