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 | 0 |
| 4 | 0 |
| 5 | 24 |
| 6 | 576 |
| 7 | 0 |
| 8 | 9216 |
| 9 | 0 |
| 10 | 20736 |
| 11 | 0 |
| 12 | 9216 |
| 13 | 0 |
| 14 | 576 |
| 15 | 4783104 |
| 16 | 25214976 |
| 17 | 62705664 |
| 18 | 98648064 |
| 19 | 109859328 |
| 20 | 87588864 |
| 21 | 54411264 |
| 22 | 23887872 |
| 23 | 9455616 |
| 24 | 1769472 |
| 25 | 663552 |
| 26 | 0 |
| 27 | 13824 |
| 28 | 248341303296 |
| 29 | 1215287525376 |
| 30 | 2855842873344 |