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 | 5 |
| 2 | 17 |
| 3 | 65 |
| 4 | 241 |
| 5 | 901 |
| 6 | 3361 |
| 7 | 12545 |
| 8 | 46817 |
| 9 | 174725 |
| 10 | 652081 |
| 11 | 2433601 |
| 12 | 9082321 |
| 13 | 33895685 |
| 14 | 126500417 |
| 15 | 472105985 |
| 16 | 1761923521 |
| 17 | 6575588101 |
| 18 | 24540428881 |
| 19 | 91586127425 |
| 20 | 341804080817 |
| 21 | 1275630195845 |
| 22 | 4760716702561 |
| 23 | 17767236614401 |
| 24 | 66308229755041 |