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 | 1 |
| 3 | -4 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | -16 |
| 8 | 0 |
| 9 | 1 |
| 10 | 80 |
| 11 | 0 |
| 12 | -40 |
| 13 | 0 |
| 14 | 1 |
| 15 | 0 |
| 16 | 640 |
| 17 | 0 |
| 18 | -80 |
| 19 | 0 |
| 20 | 1 |
| 21 | -3904 |
| 22 | 0 |
| 23 | 2800 |
| 24 | 0 |
| 25 | -140 |
| 26 | 0 |
| 27 | 1 |
| 28 | 0 |
| 29 | -49152 |
| 30 | 0 |
| 31 | 8960 |
| 32 | 0 |
| 33 | -224 |
| 34 | 0 |
| 35 | 1 |
| 36 | 354560 |
| 37 | 0 |
| 38 | -319744 |
| 39 | 0 |
| 40 | 23520 |
| 41 | 0 |
| 42 | -336 |
| 43 | 0 |
| 44 | 1 |
| 45 | 0 |
| 46 | 6225920 |
| 47 | 0 |
| 48 | -1454080 |
| 49 | 0 |
| 50 | 53760 |
| 51 | 0 |
| 52 | -480 |
| 53 | 0 |
| 54 | 1 |
| 55 | -51733504 |
| 56 | 0 |
| 57 | 54897920 |
| 58 | 0 |