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 | 1 |
| 3 | 1 |
| 4 | -10 |
| 5 | 1 |
| 6 | 576 |
| 7 | -960 |
| 8 | 352 |
| 9 | -40 |
| 10 | 1 |
| 11 | 46225 |
| 12 | -5596840 |
| 13 | 13950764 |
| 14 | -7453176 |
| 15 | 1513334 |
| 16 | -141912 |
| 17 | 6476 |
| 18 | -136 |
| 19 | 1 |
| 20 | 2000989041197056 |
| 21 | -44660812492570624 |
| 22 | 183876928237731840 |
| 23 | -255690851718529024 |
| 24 | 172580952324702208 |
| 25 | -65892492886671360 |
| 26 | 15459151516270592 |