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 | 0 |
| 3 | 8 |
| 4 | 126 |
| 5 | 0 |
| 6 | 0 |
| 7 | 31680 |
| 8 | 129492 |
| 9 | 0 |
| 10 | 0 |
| 11 | 3684312 |
| 12 | 9181784 |
| 13 | 0 |
| 14 | 0 |
| 15 | 95595072 |
| 16 | 188204958 |
| 17 | 0 |
| 18 | 0 |
| 19 | 1143217944 |
| 20 | 1959861960 |
| 21 | 0 |
| 22 | 0 |
| 23 | 8506517184 |
| 24 | 13292577672 |
| 25 | 0 |
| 26 | 0 |
| 27 | 45761541536 |
| 28 | 67074486336 |
| 29 | 0 |
| 30 | 0 |
| 31 | 195392621952 |
| 32 | 272568215700 |
| 33 | 0 |
| 34 | 0 |