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 | 19 |
| 3 | 902 |
| 4 | 53636 |
| 5 | 3771698 |
| 6 | 292587922 |
| 7 | 24422343208 |
| 8 | 2150227555324 |
| 9 | 197404215493922 |
| 10 | 18735386882618558 |
| 11 | 1827242795963079380 |
| 12 | 182291530666463403220 |
| 13 | 18537924237935355619360 |