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 | 5 |
| 3 | 25 |
| 4 | 95 |
| 5 | -275 |
| 6 | -14755 |
| 7 | -278795 |
| 8 | -4134145 |
| 9 | -49014215 |
| 10 | -304537195 |
| 11 | 7111142545 |
| 12 | 397535340575 |
| 13 | 12667519999525 |
| 14 | 327297915798125 |
| 15 | 7052174242084525 |
| 16 | 109425656597938175 |
| 17 | -88497453300450575 |
| 18 | -107470322009554282075 |
| 19 | -6297063330456696598775 |