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 | 7 |
| 3 | 142 |
| 4 | 5941 |
| 5 | 428856 |
| 6 | 47885899 |
| 7 | 7685040448 |
| 8 | 1681740027657 |
| 9 | 482368131521920 |
| 10 | 175856855224091311 |
| 11 | 79512800815739448576 |
| 12 | 43701970591391787395197 |
| 13 | 28714779850695689959247872 |