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 | -5 |
| 5 | 6 |
| 6 | 1 |
| 7 | -12 |
| 8 | 47 |
| 9 | -60 |
| 10 | 1 |
| 11 | -22 |
| 12 | 179 |
| 13 | -638 |
| 14 | 840 |
| 15 | 1 |
| 16 | -35 |
| 17 | 485 |
| 18 | -3325 |
| 19 | 11274 |
| 20 | -15120 |
| 21 | 1 |
| 22 | -51 |
| 23 | 1075 |
| 24 | -11985 |
| 25 | 74524 |
| 26 | -245004 |
| 27 | 332640 |
| 28 | 1 |
| 29 | -70 |
| 30 | 2086 |
| 31 | -34300 |
| 32 | 336049 |
| 33 | -1961470 |
| 34 | 6314664 |
| 35 | -8648640 |
| 36 | 1 |
| 37 | -92 |
| 38 | 3682 |
| 39 | -83720 |
| 40 | 1182769 |