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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 0 |
| 10 | 2 |
| 11 | 2 |
| 12 | 12 |
| 13 | 31 |
| 14 | 220 |
| 15 | 1606 |
| 16 | 16829 |
| 17 | 193900 |
| 18 | 2452820 |
| 19 | 32670331 |
| 20 | 456028487 |
| 21 | 6636066126 |
| 22 | 100135577863 |
| 23 | 1582718910743 |