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 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 172 |
| 5 | 611852 |
| 6 | 200253853704512 |
| 7 | 263735716028826427334553305221120 |
| 8 | 5609038300883759793482640992086670066496449147691597380832361377955840 |