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 | 1 |
| 1 | 2 |
| 2 | 18 |
| 3 | 268 |
| 4 | 5320 |
| 5 | 129474 |
| 6 | 3700550 |
| 7 | 121016160 |
| 8 | 4448701704 |
| 9 | 181463572394 |
| 10 | 8130511993010 |
| 11 | 396880976034092 |
| 12 | 20963000461338000 |
| 13 | 1191187898025406514 |
| 14 | 72455444438093714542 |
| 15 | 4697146562744837487104 |
| 16 | 323299667265950287087968 |