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 | 0 |
| 2 | 4 |
| 3 | 0 |
| 4 | 48 |
| 5 | 160 |
| 6 | -256 |
| 7 | 0 |
| 8 | -1792 |
| 9 | -7680 |
| 10 | 16384 |
| 11 | 0 |
| 12 | 135168 |
| 13 | 532480 |
| 14 | -1048576 |
| 15 | 0 |
| 16 | -8323072 |
| 17 | -33423360 |
| 18 | 67108864 |
| 19 | 0 |
| 20 | 537919488 |
| 21 | 2149580800 |
| 22 | -4294967296 |
| 23 | 0 |
| 24 | -34342961152 |
| 25 | -137405399040 |
| 26 | 274877906944 |
| 27 | 0 |
| 28 | 2199291691008 |
| 29 | 8796629893120 |
| 30 | -17592186044416 |
| 31 | 0 |
| 32 | -140733193388032 |
| 33 | -562941363486720 |