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 | 8 |
| 2 | 72 |
| 3 | 584 |
| 4 | 5192 |
| 5 | 42568 |
| 6 | 374856 |
| 7 | 3099208 |
| 8 | 27089992 |
| 9 | 225439304 |
| 10 | 1959198792 |
| 11 | 16387314248 |
| 12 | 141776036936 |
| 13 | 1190564148808 |
| 14 | 10264230512712 |
| 15 | 86460336036424 |
| 16 | 743371088849992 |
| 17 | 6276832595181128 |
| 18 | 53852582281580616 |
| 19 | 455569868373172808 |
| 20 | 3902135134394332232 |