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 | 2 |
| 2 | 16 |
| 3 | 102 |
| 4 | 528 |
| 5 | 2470 |
| 6 | 11016 |
| 7 | 47950 |
| 8 | 205792 |
| 9 | 874998 |
| 10 | 3694920 |
| 11 | 15519262 |
| 12 | 64899456 |
| 13 | 270415262 |
| 14 | 1123264408 |
| 15 | 4653525150 |
| 16 | 19234571968 |
| 17 | 79342610902 |
| 18 | 326704870152 |
| 19 | 1343120023678 |
| 20 | 5513861152000 |
| 21 | 22606830725598 |
| 22 | 92580354402712 |
| 23 | 378737813468542 |
| 24 | 1547884976787648 |