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 | 0 |
| 3 | 0 |
| 4 | 3 |
| 5 | 41 |
| 6 | 383 |
| 7 | 3073 |
| 8 | 22835 |
| 9 | 162517 |
| 10 | 1127399 |
| 11 | 7700835 |
| 12 | 52118506 |
| 13 | 350902046 |
| 14 | 2356532130 |
| 15 | 15813455692 |
| 16 | 106160717591 |
| 17 | 713555194577 |
| 18 | 4804401287757 |
| 19 | 32414156949765 |
| 20 | 219174260505645 |
| 21 | 1485378918978855 |
| 22 | 10089794073161037 |