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 | -2 |
| 5 | 1 |
| 6 | -1 |
| 7 | 3 |
| 8 | -3 |
| 9 | 1 |
| 10 | 2 |
| 11 | -6 |
| 12 | 7 |
| 13 | -4 |
| 14 | 1 |
| 15 | -6 |
| 16 | 18 |
| 17 | -21 |
| 18 | 13 |
| 19 | -5 |
| 20 | 1 |
| 21 | 24 |
| 22 | -72 |
| 23 | 84 |
| 24 | -52 |
| 25 | 21 |
| 26 | -6 |
| 27 | 1 |
| 28 | -120 |
| 29 | 360 |
| 30 | -420 |
| 31 | 260 |
| 32 | -105 |
| 33 | 31 |
| 34 | -7 |
| 35 | 1 |
| 36 | 720 |
| 37 | -2160 |
| 38 | 2520 |
| 39 | -1560 |
| 40 | 630 |
| 41 | -186 |
| 42 | 43 |
| 43 | -8 |
| 44 | 1 |
| 45 | -5040 |
| 46 | 15120 |
| 47 | -17640 |
| 48 | 10920 |
| 49 | -4410 |
| 50 | 1302 |
| 51 | -301 |
| 52 | 57 |
| 53 | -9 |
| 54 | 1 |