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 | -2 |
| 3 | 3 |
| 4 | 8 |
| 5 | 75 |
| 6 | -216 |
| 7 | -175 |
| 8 | -3816 |
| 9 | -36225 |
| 10 | 189800 |
| 11 | 325149 |
| 12 | 2375460 |
| 13 | 25547951 |
| 14 | 386162126 |
| 15 | -3290670825 |
| 16 | -6316583056 |
| 17 | -59290501809 |
| 18 | -310987223208 |
| 19 | -4836373835707 |
| 20 | -86500419684420 |
| 21 | 1119358992256239 |
| 22 | 3043733432729198 |
| 23 | 26408738842522959 |
| 24 | 169835931388147464 |