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 | 1 |
| 2 | 924 |
| 3 | 17153136 |
| 4 | 47768769048 |
| 5 | 83659800759150 |
| 6 | 202929004783993742 |