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 | -3 |
| 9 | 1 |
| 10 | 0 |
| 11 | -17 |
| 12 | 17 |
| 13 | -6 |
| 14 | 1 |
| 15 | 0 |
| 16 | 155 |
| 17 | -155 |
| 18 | 55 |
| 19 | -10 |
| 20 | 1 |
| 21 | 0 |
| 22 | -2073 |
| 23 | 2073 |
| 24 | -736 |
| 25 | 135 |
| 26 | -15 |
| 27 | 1 |
| 28 | 0 |
| 29 | 38227 |
| 30 | -38227 |
| 31 | 13573 |
| 32 | -2492 |
| 33 | 280 |
| 34 | -21 |
| 35 | 1 |
| 36 | 0 |
| 37 | -929569 |
| 38 | 929569 |
| 39 | -330058 |
| 40 | 60605 |
| 41 | -6818 |
| 42 | 518 |
| 43 | -28 |
| 44 | 1 |
| 45 | 0 |
| 46 | 28820619 |
| 47 | -28820619 |
| 48 | 10233219 |
| 49 | -1879038 |
| 50 | 211419 |
| 51 | -16086 |
| 52 | 882 |
| 53 | -36 |
| 54 | 1 |
| 55 | 0 |
| 56 | -1109652905 |