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 | 1 |
| 4 | 4 |
| 5 | 0 |
| 6 | 16 |
| 7 | 0 |
| 8 | 4 |
| 9 | 36 |
| 10 | 0 |
| 11 | 324 |
| 12 | 0 |
| 13 | 324 |
| 14 | 0 |
| 15 | 36 |
| 16 | 576 |
| 17 | 0 |
| 18 | 9216 |
| 19 | 0 |
| 20 | 20736 |
| 21 | 0 |
| 22 | 9216 |
| 23 | 0 |
| 24 | 576 |
| 25 | 14400 |
| 26 | 0 |
| 27 | 360000 |
| 28 | 0 |
| 29 | 1440000 |
| 30 | 0 |
| 31 | 1440000 |
| 32 | 0 |
| 33 | 360000 |
| 34 | 0 |
| 35 | 14400 |
| 36 | 518400 |
| 37 | 0 |
| 38 | 18662400 |
| 39 | 0 |
| 40 | 116640000 |
| 41 | 0 |
| 42 | 207360000 |
| 43 | 0 |
| 44 | 116640000 |