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) |
|---|---|
| 2 | -1 |
| 3 | -2 |
| 4 | 0 |
| 5 | 0 |
| 6 | -32 |
| 7 | 256 |
| 8 | 0 |
| 9 | 0 |
| 10 | -8192 |
| 11 | 0 |
| 12 | -262144 |
| 13 | 5242880 |
| 14 | 0 |
| 15 | 0 |
| 16 | -33554432 |
| 17 | 0 |
| 18 | -2684354560 |
| 19 | 0 |
| 20 | 0 |
| 21 | 8589934592000 |
| 22 | 0 |
| 23 | 0 |
| 24 | 932385860354048 |
| 25 | 160159261748363264 |
| 26 | -1125899906842624 |
| 27 | 0 |
| 28 | 0 |
| 29 | -225179981368524800 |
| 30 | 5260204364768739328 |
| 31 | 0 |
| 32 | 0 |