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 | 13 |
| 2 | 133 |
| 3 | 1225 |
| 4 | 10633 |
| 5 | 88837 |
| 6 | 722701 |
| 7 | 5764801 |
| 8 | 45294865 |
| 9 | 351652861 |
| 10 | 2703691669 |
| 11 | 20620693177 |
| 12 | 156208812697 |
| 13 | 1176509412085 |
| 14 | 8816899947037 |
| 15 | 65787638066353 |
| 16 | 488998835524129 |
| 17 | 3622389432086509 |
| 18 | 26752509108528805 |
| 19 | 197038045347164329 |