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 | 0 |
| 1 | 2 |
| 2 | 1332 |
| 3 | 166376 |
| 4 | 13651920 |
| 5 | 973242272 |
| 6 | 65499561792 |
| 7 | 4294977781376 |
| 8 | 278176525712640 |
| 9 | 17908846064302592 |
| 10 | 1149543810255025152 |
| 11 | 73678889946730981376 |
| 12 | 4718907718699422044160 |
| 13 | 302120774441963815411712 |
| 14 | 19339271338993904793894912 |
| 15 | 1237826702489967325274341376 |