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 | 0 |
| 2 | 4 |
| 3 | 8 |
| 4 | 81 |
| 5 | 392 |
| 6 | 2500 |
| 7 | 14112 |
| 8 | 83521 |
| 9 | 484128 |
| 10 | 2829124 |
| 11 | 16473800 |
| 12 | 96059601 |
| 13 | 559785800 |
| 14 | 3262922884 |
| 15 | 19017180288 |
| 16 | 110841719041 |
| 17 | 646029804672 |
| 18 | 3765346202500 |
| 19 | 21946028005832 |
| 20 | 127910874833361 |
| 21 | 745519107896648 |