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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 8 |
| 5 | 37 |
| 6 | 248 |
| 7 | 1749 |
| 8 | 14284 |
| 9 | 130343 |
| 10 | 1318194 |
| 11 | 14630853 |
| 12 | 176881314 |
| 13 | 2313878809 |
| 14 | 32567413038 |
| 15 | 490762544907 |
| 16 | 7883735348152 |
| 17 | 134496767915753 |
| 18 | 2428518101193448 |
| 19 | 46270707955530689 |
| 20 | 927734890186657436 |