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 | -1054 |
| 3 | -6340 |
| 4 | 3332716 |
| 5 | 33496312 |
| 6 | -17563075016 |
| 7 | -247760738608 |
| 8 | 129576612091280 |
| 9 | 2356200115760672 |
| 10 | -1229116100101646816 |
| 11 | -27386829424951203392 |
| 12 | 14249679514133063237824 |
| 13 | 376202545407446604740480 |
| 14 | -195237686946571258563550336 |
| 15 | -5962787476468241626543090432 |