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 | -4 |
| 2 | -88 |
| 3 | -992 |
| 4 | -19360 |
| 5 | -97152 |
| 6 | -4296448 |
| 7 | 4539392 |
| 8 | -568015360 |
| 9 | -127621120 |
| 10 | -39357927424 |
| 11 | 2424998313984 |
| 12 | -38804685471744 |
| 13 | 799759166930944 |
| 14 | 4879962868940800 |
| 15 | 41563181340426240 |
| 16 | 585185165832486912 |
| 17 | 55834295603426754560 |
| 18 | -75535223925056208896 |