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 | 0 |
| 1 | 4 |
| 2 | 3 |
| 3 | 19 |
| 4 | 160 |
| 5 | 1744 |
| 6 | 644 |
| 7 | 2529 |
| 8 | 183296 |
| 9 | 3763456 |
| 10 | 4317632 |
| 11 | 54743776 |
| 12 | 1013549056 |
| 13 | 30594128896 |
| 14 | 35618973952 |
| 15 | 10392576224 |
| 16 | 3111643512832 |
| 17 | 123968232030208 |
| 18 | 48501417558016 |
| 19 | 1083228572868608 |
| 20 | 4080033616887808 |
| 21 | 188557135970304 |
| 22 | 3781715948011520 |