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 | 2 |
| 2 | 9 |
| 3 | 44 |
| 4 | 235 |
| 5 | 1296 |
| 6 | 7329 |
| 7 | 42104 |
| 8 | 244719 |
| 9 | 1434840 |
| 10 | 8470517 |
| 11 | 50280372 |
| 12 | 299806572 |
| 13 | 1794382548 |
| 14 | 10773855210 |
| 15 | 64865425760 |
| 16 | 391457133672 |
| 17 | 2367314649522 |
| 18 | 14342441005900 |
| 19 | 87035702613500 |
| 20 | 528938145043707 |
| 21 | 3218713327609648 |