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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 6 |
| 6 | 28 |
| 7 | 83 |
| 8 | 289 |
| 9 | 1030 |
| 10 | 3860 |
| 11 | 14154 |
| 12 | 53222 |
| 13 | 202001 |
| 14 | 771255 |
| 15 | 2945803 |
| 16 | 11304541 |
| 17 | 43564276 |
| 18 | 168413249 |
| 19 | 652292925 |
| 20 | 2531493604 |
| 21 | 9845752518 |
| 22 | 38372748112 |