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 | 0 |
| 1 | 1 |
| 2 | 18 |
| 3 | 207 |
| 4 | 2134 |
| 5 | 21465 |
| 6 | 214866 |
| 7 | 2149003 |
| 8 | 21490542 |
| 9 | 214906149 |
| 10 | 2149062490 |
| 11 | 21490626231 |
| 12 | 214906264038 |
| 13 | 2149062642577 |
| 14 | 21490626428514 |
| 15 | 214906264288515 |
| 16 | 2149062642889246 |
| 17 | 21490626428897373 |
| 18 | 214906264288979562 |
| 19 | 2149062642889802479 |
| 20 | 21490626428898032790 |