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 | 16 |
| 3 | -424 |
| 4 | 2944 |
| 5 | -70240 |
| 6 | 70873856 |
| 7 | -212648576 |
| 8 | 98650550272 |
| 9 | -90228445612544 |
| 10 | 19078660567134208 |
| 11 | -2034677178643867648 |
| 12 | 123160010212358914048 |
| 13 | -19182197131374977024 |
| 14 | 228111332170536254898176 |
| 15 | -51166426240975948419354886144 |