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 | 4 |
| 4 | 16 |
| 5 | 81 |
| 6 | 486 |
| 7 | 3403 |
| 8 | 27224 |
| 9 | 245016 |
| 10 | 2450160 |
| 11 | 26951761 |
| 12 | 323421132 |
| 13 | 4204474717 |
| 14 | 58862646038 |
| 15 | 882939690570 |
| 16 | 14127035049120 |
| 17 | 240159595835041 |
| 18 | 4322872725030738 |
| 19 | 82134581775584023 |
| 20 | 1642691635511680460 |