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 | 0 |
| 4 | -3 |
| 5 | 1 |
| 6 | 0 |
| 7 | 5 |
| 8 | -6 |
| 9 | 1 |
| 10 | 0 |
| 11 | -14 |
| 12 | 23 |
| 13 | -10 |
| 14 | 1 |
| 15 | 0 |
| 16 | 54 |
| 17 | -105 |
| 18 | 65 |
| 19 | -15 |
| 20 | 1 |
| 21 | 0 |
| 22 | -264 |
| 23 | 574 |
| 24 | -435 |
| 25 | 145 |
| 26 | -21 |
| 27 | 1 |
| 28 | 0 |
| 29 | 1560 |
| 30 | -3682 |
| 31 | 3199 |
| 32 | -1330 |
| 33 | 280 |
| 34 | -28 |
| 35 | 1 |
| 36 | 0 |
| 37 | -10800 |
| 38 | 27180 |
| 39 | -26124 |
| 40 | 12649 |
| 41 | -3360 |
| 42 | 490 |
| 43 | -36 |
| 44 | 1 |
| 45 | 0 |
| 46 | 85680 |
| 47 | -227196 |
| 48 | 236312 |
| 49 | -128205 |
| 50 | 40089 |
| 51 | -7434 |
| 52 | 798 |
| 53 | -45 |
| 54 | 1 |