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 | 4 |
| 2 | 28 |
| 3 | 364 |
| 4 | 10626 |
| 5 | 850668 |
| 6 | 218618940 |
| 7 | 198773423848 |
| 8 | 669741609663270 |
| 9 | 8493008777332033900 |
| 10 | 405943250253048290447028 |
| 11 | 72938914603968404495709630360 |
| 12 | 49143490709866058459392200362497820 |