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 | 4 |
| 2 | 11 |
| 3 | 37 |
| 4 | 137 |
| 5 | 529 |
| 6 | 2081 |
| 7 | 8257 |
| 8 | 32897 |
| 9 | 131329 |
| 10 | 524801 |
| 11 | 2098177 |
| 12 | 8390657 |
| 13 | 33558529 |
| 14 | 134225921 |
| 15 | 536887297 |
| 16 | 2147516417 |
| 17 | 8590000129 |
| 18 | 34359869441 |
| 19 | 137439215617 |
| 20 | 549756338177 |
| 21 | 2199024304129 |
| 22 | 8796095119361 |
| 23 | 35184376283137 |
| 24 | 140737496743937 |
| 25 | 562949970198529 |