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 | 3 |
| 2 | 40 |
| 3 | 852 |
| 4 | 22368 |
| 5 | 822528 |
| 6 | 38772864 |
| 7 | 2462728320 |
| 8 | 189512165376 |
| 9 | 18739021676544 |
| 10 | 2147802505795584 |
| 11 | 305748136551647232 |
| 12 | 48922389407097077760 |
| 13 | 9484975881651606847488 |
| 14 | 2021636445616137313124352 |
| 15 | 512419728510195503179825152 |
| 16 | 140423343538080744846410121216 |