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 | 15 |
| 3 | 220 |
| 4 | 10626 |
| 5 | 1712304 |
| 6 | 927048304 |
| 7 | 1708566412608 |
| 8 | 10895665708319184 |
| 9 | 244373929798154341120 |
| 10 | 19561373281624772727757056 |
| 11 | 5658395223117478029148167447552 |
| 12 | 5975982733408602667847206514763365888 |