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 | 9 |
| 2 | 137 |
| 3 | 2185 |
| 4 | 34953 |
| 5 | 559241 |
| 6 | 8947849 |
| 7 | 143165577 |
| 8 | 2290649225 |
| 9 | 36650387593 |
| 10 | 586406201481 |
| 11 | 9382499223689 |
| 12 | 150119987579017 |
| 13 | 2401919801264265 |
| 14 | 38430716820228233 |
| 15 | 614891469123651721 |
| 16 | 9838263505978427529 |
| 17 | 157412216095654840457 |
| 18 | 2518595457530477447305 |