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) |
|---|---|
| 3 | 1 |
| 4 | 10 |
| 5 | 111 |
| 6 | 1468 |
| 7 | 22940 |
| 8 | 416250 |
| 9 | 8626660 |
| 10 | 201349672 |
| 11 | 5230931454 |
| 12 | 149783426470 |
| 13 | 4688281021490 |
| 14 | 159284662406460 |
| 15 | 5838769123729984 |
| 16 | 229711022253150382 |
| 17 | 9655348958575618320 |
| 18 | 431845990498159342000 |
| 19 | 20479127764425617465660 |
| 20 | 1026429489947790074019978 |