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) |
|---|---|
| 1 | 7 |
| 2 | 49 |
| 3 | 295 |
| 4 | 1793 |
| 5 | 10871 |
| 6 | 65937 |
| 7 | 399911 |
| 8 | 2425505 |
| 9 | 14710935 |
| 10 | 89223345 |
| 11 | 541148807 |
| 12 | 3282123457 |
| 13 | 19906418039 |
| 14 | 120734483153 |
| 15 | 732267120743 |
| 16 | 4441275782369 |
| 17 | 26936796718423 |
| 18 | 163374456576241 |
| 19 | 990882967287879 |
| 20 | 6009807624994561 |