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 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 30 |
| 5 | 84 |
| 6 | 227 |
| 7 | 603 |
| 8 | 1589 |
| 9 | 4172 |
| 10 | 10936 |
| 11 | 28646 |
| 12 | 75013 |
| 13 | 196405 |
| 14 | 514215 |
| 15 | 1346254 |
| 16 | 3524562 |
| 17 | 9227448 |
| 18 | 24157799 |
| 19 | 63245967 |
| 20 | 165580121 |
| 21 | 433494416 |
| 22 | 1134903148 |
| 23 | 2971215050 |
| 24 | 7778742025 |
| 25 | 20365011049 |
| 26 | 53316291147 |
| 27 | 139583862418 |