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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | -6560 |
| 4 | 1 |
| 5 | 390626 |
| 6 | -6560 |
| 7 | -5764800 |
| 8 | 1 |
| 9 | 43040161 |
| 10 | 390626 |
| 11 | -214358880 |
| 12 | -6560 |
| 13 | 815730722 |
| 14 | -5764800 |
| 15 | -2562506560 |
| 16 | 1 |
| 17 | 6975757442 |
| 18 | 43040161 |
| 19 | -16983563040 |
| 20 | 390626 |
| 21 | 37817088000 |
| 22 | -214358880 |
| 23 | -78310985280 |
| 24 | -6560 |
| 25 | 152588281251 |
| 26 | 815730722 |