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 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -1 |
| 5 | -1 |
| 6 | 1 |
| 7 | -1 |
| 8 | -4 |
| 9 | 0 |
| 10 | 1 |
| 11 | -1 |
| 12 | -16 |
| 13 | -23 |
| 14 | 0 |
| 15 | 1 |
| 16 | -1 |
| 17 | -64 |
| 18 | -713 |
| 19 | -223 |
| 20 | 1 |
| 21 | 1 |
| 22 | -1 |
| 23 | -256 |
| 24 | -19619 |
| 25 | -64687 |
| 26 | -2767 |
| 27 | 0 |
| 28 | 1 |
| 29 | -1 |
| 30 | -1024 |
| 31 | -531185 |
| 32 | -16755517 |
| 33 | -9688545 |
| 34 | -42268 |
| 35 | 1 |
| 36 | 1 |
| 37 | -1 |
| 38 | -4096 |
| 39 | -14347883 |
| 40 | -4294403215 |
| 41 | -30499543213 |
| 42 | -2165715003 |
| 43 | -759008 |
| 44 | 0 |
| 45 | 1 |
| 46 | -1 |
| 47 | -16384 |