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) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 11 |
| 6 | 35 |
| 7 | 111 |
| 8 | 343 |
| 9 | 1049 |
| 10 | 3177 |
| 11 | 9559 |
| 12 | 28611 |
| 13 | 85293 |
| 14 | 253461 |
| 15 | 751296 |
| 16 | 2222442 |
| 17 | 6563598 |
| 18 | 19359022 |
| 19 | 57038247 |
| 20 | 167911721 |
| 21 | 493972165 |
| 22 | 1452419661 |
| 23 | 4268753126 |
| 24 | 12542145548 |
| 25 | 36841741320 |
| 26 | 108202146520 |
| 27 | 317748977715 |
| 28 | 933052724721 |
| 29 | 2739805981773 |