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 | 6 |
| 2 | 56 |
| 3 | 576 |
| 4 | 6216 |
| 5 | 68976 |
| 6 | 779456 |
| 7 | 8921856 |
| 8 | 103098976 |
| 9 | 1200177216 |
| 10 | 14053176576 |
| 11 | 165337030656 |
| 12 | 1952904166656 |
| 13 | 23143984805376 |
| 14 | 275062611081216 |
| 15 | 3277130498482176 |
| 16 | 39128126836409856 |
| 17 | 468065027383059456 |
| 18 | 5608576020851019776 |
| 19 | 67305503084237193216 |
| 20 | 808786974964809035776 |