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 | -3 |
| 7 | -3 |
| 8 | -3 |
| 9 | 1 |
| 10 | -15 |
| 11 | -12 |
| 12 | -6 |
| 13 | -4 |
| 14 | 1 |
| 15 | -105 |
| 16 | -75 |
| 17 | -30 |
| 18 | -10 |
| 19 | -5 |
| 20 | 1 |
| 21 | -945 |
| 22 | -630 |
| 23 | -225 |
| 24 | -60 |
| 25 | -15 |
| 26 | -6 |
| 27 | 1 |
| 28 | -10395 |
| 29 | -6615 |
| 30 | -2205 |
| 31 | -525 |
| 32 | -105 |
| 33 | -21 |
| 34 | -7 |
| 35 | 1 |
| 36 | -135135 |
| 37 | -83160 |
| 38 | -26460 |
| 39 | -5880 |
| 40 | -1050 |
| 41 | -168 |
| 42 | -28 |
| 43 | -8 |
| 44 | 1 |
| 45 | -2027025 |
| 46 | -1216215 |
| 47 | -374220 |
| 48 | -79380 |
| 49 | -13230 |
| 50 | -1890 |
| 51 | -252 |
| 52 | -36 |
| 53 | -9 |
| 54 | 1 |