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 | 2 |
| 1 | 11 |
| 2 | 65 |
| 3 | 389 |
| 4 | 2333 |
| 5 | 13997 |
| 6 | 83981 |
| 7 | 503885 |
| 8 | 3023309 |
| 9 | 18139853 |
| 10 | 108839117 |
| 11 | 653034701 |
| 12 | 3918208205 |
| 13 | 23509249229 |
| 14 | 141055495373 |
| 15 | 846332972237 |
| 16 | 5077997833421 |
| 17 | 30467987000525 |
| 18 | 182807922003149 |
| 19 | 1096847532018893 |
| 20 | 6581085192113357 |
| 21 | 39486511152680141 |