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 | 29 |
| 1 | 121 |
| 2 | 242 |
| 3 | 484 |
| 4 | 968 |
| 5 | 1837 |
| 6 | 9218 |
| 7 | 17347 |
| 8 | 91718 |
| 9 | 173437 |
| 10 | 907808 |
| 11 | 1716517 |
| 12 | 8872688 |
| 13 | 17735476 |
| 14 | 85189247 |
| 15 | 159487405 |
| 16 | 664272356 |
| 17 | 1317544822 |
| 18 | 3602001953 |
| 19 | 7193004016 |
| 20 | 13297007933 |
| 21 | 47267087164 |