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 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 20 |
| 7 | 48 |
| 8 | 133 |
| 9 | 374 |
| 10 | 1124 |
| 11 | 3439 |
| 12 | 10923 |
| 13 | 35245 |
| 14 | 116128 |
| 15 | 387729 |
| 16 | 1312038 |
| 17 | 4485906 |
| 18 | 15486546 |
| 19 | 53900520 |
| 20 | 188998450 |
| 21 | 667062919 |
| 22 | 2368440477 |
| 23 | 8454560144 |
| 24 | 30328595227 |
| 25 | 109285433191 |
| 26 | 395425965732 |
| 27 | 1436219868659 |
| 28 | 5234881134074 |
| 29 | 19143123415166 |
| 30 | 70216752517419 |