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 | 4 |
| 2 | 24 |
| 3 | 188 |
| 4 | 1368 |
| 5 | 10572 |
| 6 | 81376 |
| 7 | 637148 |
| 8 | 5007560 |
| 9 | 39638728 |
| 10 | 314980912 |
| 11 | 2513038452 |
| 12 | 20109809792 |
| 13 | 161359033480 |
| 14 | 1297640775272 |
| 15 | 10456351280264 |