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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 35 |
| 7 | 100 |
| 8 | 298 |
| 9 | 926 |
| 10 | 2995 |
| 11 | 10045 |
| 12 | 34871 |
| 13 | 125040 |
| 14 | 462283 |
| 15 | 1759340 |
| 16 | 6882479 |
| 17 | 27639252 |
| 18 | 113809750 |
| 19 | 479993898 |
| 20 | 2071411798 |
| 21 | 9138568984 |
| 22 | 41182104446 |
| 23 | 189418562699 |
| 24 | 888607018626 |
| 25 | 4248949407337 |
| 26 | 20695172225549 |
| 27 | 102617378820155 |
| 28 | 517728263280060 |