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 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | -4 |
| 6 | 8 |
| 7 | -16 |
| 8 | 32 |
| 9 | -56 |
| 10 | 88 |
| 11 | -112 |
| 12 | 64 |
| 13 | 240 |
| 14 | -1264 |
| 15 | 4064 |
| 16 | -10814 |
| 17 | 25500 |
| 18 | -54200 |
| 19 | 102832 |
| 20 | -166020 |
| 21 | 190808 |
| 22 | 22304 |
| 23 | -1058880 |
| 24 | 4412424 |
| 25 | -13496544 |
| 26 | 35306480 |
| 27 | -82326496 |
| 28 | 172081840 |
| 29 | -315115328 |
| 30 | 464910368 |
| 31 | -363016000 |
| 32 | -871587808 |
| 33 | 5713552456 |
| 34 | -20289991016 |