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 | -1 |
| 5 | 1 |
| 6 | -3 |
| 7 | 3 |
| 8 | -3 |
| 9 | 1 |
| 10 | 15 |
| 11 | -15 |
| 12 | 15 |
| 13 | -5 |
| 14 | 1 |
| 15 | -165 |
| 16 | 165 |
| 17 | -165 |
| 18 | 55 |
| 19 | -11 |
| 20 | 1 |
| 21 | 3465 |
| 22 | -3465 |
| 23 | 3465 |
| 24 | -1155 |
| 25 | 231 |
| 26 | -21 |
| 27 | 1 |
| 28 | -148995 |
| 29 | 148995 |
| 30 | -148995 |
| 31 | 49665 |
| 32 | -9933 |
| 33 | 903 |
| 34 | -43 |
| 35 | 1 |
| 36 | 12664575 |
| 37 | -12664575 |
| 38 | 12664575 |