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) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 12 |
| 4 | 304 |
| 5 | 27664 |
| 6 | 6990848 |
| 7 | 5179182272 |
| 8 | 11396324423680 |
| 9 | 74944172893348096 |
| 10 | 1476405354971703541760 |
| 11 | 87208352627656970763963392 |
| 12 | 15450530398306943408624578330624 |
| 13 | 8211400756816955708062672329408385024 |