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 | 2 |
| 2 | 8 |
| 3 | 41 |
| 4 | 250 |
| 5 | 1757 |
| 6 | 13917 |
| 7 | 122166 |
| 8 | 1173662 |
| 9 | 12222605 |
| 10 | 136927351 |
| 11 | 1639768418 |
| 12 | 20880556880 |
| 13 | 281460326864 |
| 14 | 4000651782511 |
| 15 | 59761935358025 |
| 16 | 935445106491702 |
| 17 | 15303039199768237 |
| 18 | 261030618751031385 |
| 19 | 4632889302298054713 |