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 | 11 |
| 3 | 53 |
| 4 | 237 |
| 5 | 1013 |
| 6 | 4196 |
| 7 | 16992 |
| 8 | 67647 |
| 9 | 265743 |
| 10 | 1032827 |
| 11 | 3979023 |
| 12 | 15217248 |
| 13 | 57835016 |
| 14 | 218636365 |
| 15 | 822691425 |
| 16 | 3083074193 |
| 17 | 11512489353 |
| 18 | 42851360088 |
| 19 | 159043175322 |
| 20 | 588767623587 |
| 21 | 2174488780469 |
| 22 | 8013945343961 |
| 23 | 29477541831841 |
| 24 | 108233492257428 |
| 25 | 396751988675780 |