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 | 62 |
| 3 | 5052 |
| 4 | 1087104 |
| 5 | 487424520 |
| 6 | 393702654960 |
| 7 | 519740602925040 |
| 8 | 1046019551260199040 |
| 9 | 3046052768591313895680 |
| 10 | 12322848899623787148556800 |
| 11 | 67036205966744406283600262400 |
| 12 | 477463744343745629221074425625600 |
| 13 | 4354451197836949908463868034925593600 |