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 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 57 |
| 5 | 256 |
| 6 | 2763 |
| 7 | 17408 |
| 8 | 250737 |
| 9 | 2031616 |
| 10 | 36581523 |
| 11 | 362283008 |
| 12 | 7828053417 |
| 13 | 91620376576 |
| 14 | 2309644635483 |
| 15 | 31191159799808 |
| 16 | 898621108880097 |
| 17 | 13753735117275136 |
| 18 | 445777636063460643 |
| 19 | 7625476699018231808 |