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 | 2 |
| 3 | 6 |
| 4 | 18 |
| 5 | 57 |
| 6 | 188 |
| 7 | 651 |
| 8 | 2336 |
| 9 | 8719 |
| 10 | 33741 |
| 11 | 135185 |
| 12 | 559908 |
| 13 | 2394326 |
| 14 | 10557283 |
| 15 | 47943126 |
| 16 | 223987316 |
| 17 | 1075455181 |
| 18 | 5301593544 |
| 19 | 26807904317 |
| 20 | 138924912857 |
| 21 | 737220195148 |
| 22 | 4002876571636 |
| 23 | 22221898966507 |
| 24 | 126042573704637 |
| 25 | 729944250603862 |
| 26 | 4313430995825272 |