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 | 1 |
| 2 | 30 |
| 3 | 381 |
| 4 | 4092 |
| 5 | 40955 |
| 6 | 393210 |
| 7 | 3670009 |
| 8 | 33554424 |
| 9 | 301989879 |
| 10 | 2684354550 |
| 11 | 23622320117 |
| 12 | 206158430196 |
| 13 | 1786706395123 |
| 14 | 15393162788850 |
| 15 | 131941395333105 |
| 16 | 1125899906842608 |
| 17 | 9570149208162287 |
| 18 | 81064793292668910 |
| 19 | 684547143360315373 |