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 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 2 |
| 11 | 160 |
| 12 | 6056 |
| 13 | 161136 |
| 14 | 3661824 |
| 15 | 76972416 |
| 16 | 1572313392 |
| 17 | 32096768008 |
| 18 | 665456850864 |
| 19 | 14144815265510 |
| 20 | 309931658271656 |
| 21 | 7021414359095808 |