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 | -3 |
| 5 | -1 |
| 6 | 1 |
| 7 | -6 |
| 8 | -10 |
| 9 | 1 |
| 10 | 1 |
| 11 | -10 |
| 12 | -50 |
| 13 | 35 |
| 14 | 1 |
| 15 | 1 |
| 16 | -15 |
| 17 | -175 |
| 18 | 490 |
| 19 | 126 |
| 20 | -1 |
| 21 | 1 |
| 22 | -21 |
| 23 | -490 |
| 24 | 4116 |
| 25 | 5292 |
| 26 | -462 |
| 27 | -1 |
| 28 | 1 |
| 29 | -28 |
| 30 | -1176 |
| 31 | 24696 |
| 32 | 116424 |
| 33 | -60984 |
| 34 | -1716 |
| 35 | 1 |
| 36 | 1 |
| 37 | -36 |
| 38 | -2520 |
| 39 | 116424 |
| 40 | 1646568 |
| 41 | -3737448 |
| 42 | -736164 |
| 43 | 6435 |
| 44 | 1 |
| 45 | 1 |
| 46 | -45 |
| 47 | -4950 |
| 48 | 457380 |
| 49 | 16818516 |
| 50 | -133613766 |
| 51 | -131589315 |
| 52 | 9202050 |
| 53 | 24310 |
| 54 | -1 |