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 | 2 |
| 2 | 20 |
| 3 | 8 |
| 4 | 464 |
| 5 | -736 |
| 6 | 12608 |
| 7 | -42880 |
| 8 | 388352 |
| 9 | -1805824 |
| 10 | 12932096 |
| 11 | -69203968 |
| 12 | 448778240 |
| 13 | -2558451712 |
| 14 | 15887581184 |
| 15 | -93178003456 |
| 16 | 567657955328 |
| 17 | -3371587993600 |
| 18 | 20366966915072 |
| 19 | -121652045676544 |
| 20 | 732111297314816 |
| 21 | -4383871690866688 |
| 22 | 26338414517288960 |