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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -6 |
| 5 | 1 |
| 6 | 1 |
| 7 | -15 |
| 8 | 47 |
| 9 | -1 |
| 10 | 1 |
| 11 | -40 |
| 12 | 270 |
| 13 | -488 |
| 14 | 1 |
| 15 | 1 |
| 16 | -165 |
| 17 | 1738 |
| 18 | -5866 |
| 19 | 5829 |
| 20 | -1 |
| 21 | 1 |
| 22 | -1074 |
| 23 | 15695 |
| 24 | -80060 |
| 25 | 156495 |
| 26 | -74674 |
| 27 | 1 |
| 28 | 1 |
| 29 | -9039 |
| 30 | 181581 |
| 31 | -1360515 |
| 32 | 4552003 |
| 33 | -5997165 |
| 34 | 997295 |
| 35 | -1 |
| 36 | 1 |
| 37 | -86700 |
| 38 | 2566036 |
| 39 | -28081556 |