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 | 3 |
| 3 | 6 |
| 4 | 12 |
| 5 | 48 |
| 6 | 336 |
| 7 | 3696 |
| 8 | 59136 |
| 9 | 1300992 |
| 10 | 37728768 |
| 11 | 1395964416 |
| 12 | 64214363136 |
| 13 | 3596004335616 |
| 14 | 240932290486272 |
| 15 | 19033650948415488 |
| 16 | 1751095887254224896 |
| 17 | 185616164048947838976 |
| 18 | 22459555849922688516096 |