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 | 65535 |
| 1 | 16711935 |
| 2 | 252645135 |
| 3 | 858993459 |
| 4 | 1431655765 |
| 5 | 1789569706 |
| 6 | 2527709560 |
| 7 | 5047409558 |
| 8 | 11322905375 |
| 9 | 20900211843 |
| 10 | 39100503852 |
| 11 | 60375175654 |
| 12 | 81769697955 |
| 13 | 160265870155 |