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 | 0 |
| 2 | 1 |
| 3 | 8 |
| 4 | 97 |
| 5 | 1024 |
| 6 | 20450 |
| 7 | 279936 |
| 8 | 7509953 |
| 9 | 144295424 |
| 10 | 4570291850 |
| 11 | 100000000000 |
| 12 | 4491754172274 |
| 13 | 106993205379072 |
| 14 | 5221973073321002 |
| 15 | 171975117132398592 |
| 16 | 8931527427394008833 |
| 17 | 295147905179352825856 |
| 18 | 20290116242888952838355 |
| 19 | 708235345355337676357632 |
| 20 | 51879761166564630630389778 |