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 | 3 |
| 2 | 10 |
| 3 | 34 |
| 4 | 117 |
| 5 | 405 |
| 6 | 1407 |
| 7 | 4899 |
| 8 | 17083 |
| 9 | 59629 |
| 10 | 208284 |
| 11 | 727900 |
| 12 | 2544751 |
| 13 | 8898873 |
| 14 | 31125138 |
| 15 | 108881166 |
| 16 | 380928795 |
| 17 | 1332824049 |
| 18 | 4663705782 |
| 19 | 16319702046 |
| 20 | 57109857519 |
| 21 | 199859075307 |
| 22 | 699435489795 |
| 23 | 2447823832671 |
| 24 | 8566818534141 |
| 25 | 29982268505595 |
| 26 | 104933418068332 |