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 | -5 |
| 2 | -50 |
| 3 | -3875 |
| 4 | 2500 |
| 5 | -2046250 |
| 6 | -12409375 |
| 7 | -1087687500 |
| 8 | 13232343750 |
| 9 | -907225000000 |
| 10 | 1545669140625 |
| 11 | -362705679687500 |
| 12 | 6007095839843750 |
| 13 | -224713698632812500 |
| 14 | 2118331116210937500 |
| 15 | -226812683210205078125 |
| 16 | 4765872641563720703125 |