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 | 3 |
| 3 | 6 |
| 4 | 21 |
| 5 | 54 |
| 6 | 186 |
| 7 | 479 |
| 8 | 1938 |
| 9 | 5795 |
| 10 | 22888 |
| 11 | 70781 |
| 12 | 286443 |
| 13 | 861463 |
| 14 | 3592105 |
| 15 | 11492256 |
| 16 | 39274353 |
| 17 | 148852401 |
| 18 | 613876868 |
| 19 | 1917516257 |
| 20 | 8511689170 |
| 21 | 25445125513 |
| 22 | 100975365920 |
| 23 | 390096404027 |
| 24 | 1666653892303 |
| 25 | 5319341488465 |