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 | 3 |
| 2 | 21 |
| 3 | 195 |
| 4 | 2241 |
| 5 | 30483 |
| 6 | 476469 |
| 7 | 8383203 |
| 8 | 163532385 |
| 9 | 3496040163 |
| 10 | 81159271029 |
| 11 | 2030708891907 |
| 12 | 54427341596769 |
| 13 | 1554460972941555 |
| 14 | 47097454520401749 |
| 15 | 1507969940021725347 |
| 16 | 50850987639474121281 |
| 17 | 1800630391669594010307 |
| 18 | 66775808799868618561365 |