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 | 0 |
| 4 | -1 |
| 5 | 1 |
| 6 | 0 |
| 7 | 3 |
| 8 | -1 |
| 9 | -3 |
| 10 | 1 |
| 11 | 0 |
| 12 | -15 |
| 13 | 10 |
| 14 | -1 |
| 15 | 15 |
| 16 | -4 |
| 17 | -6 |
| 18 | 1 |
| 19 | 0 |
| 20 | 105 |
| 21 | -105 |
| 22 | 10 |
| 23 | 15 |
| 24 | -1 |
| 25 | -105 |
| 26 | 60 |
| 27 | -5 |
| 28 | 45 |
| 29 | -10 |
| 30 | -10 |
| 31 | 1 |
| 32 | 0 |
| 33 | -945 |
| 34 | 1260 |
| 35 | -280 |
| 36 | -210 |
| 37 | 35 |
| 38 | 21 |
| 39 | -1 |
| 40 | 945 |
| 41 | -840 |
| 42 | 70 |
| 43 | 105 |
| 44 | -6 |
| 45 | -420 |
| 46 | 210 |
| 47 | -15 |
| 48 | 105 |
| 49 | -20 |
| 50 | -15 |
| 51 | 1 |