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 | 39 |
| 4 | 2925 |
| 5 | 1582425 |
| 6 | 7410496275 |
| 7 | 350464600333575 |
| 8 | 191295845123076910125 |
| 9 | 1355763582602823185129417625 |
| 10 | 138623522325287867599380791765497875 |
| 11 | 224935042709004795568466587349227029537282375 |
| 12 | 6318777956744220129890735589019782971247629409914638125 |