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 | 0 |
| 1 | -1 |
| 2 | 1 |
| 3 | 2 |
| 4 | -4 |
| 5 | 2 |
| 6 | -16 |
| 7 | 48 |
| 8 | -48 |
| 9 | 16 |
| 10 | 272 |
| 11 | -1088 |
| 12 | 1632 |
| 13 | -1088 |
| 14 | 272 |
| 15 | -7936 |
| 16 | 39680 |
| 17 | -79360 |
| 18 | 79360 |
| 19 | -39680 |
| 20 | 7936 |
| 21 | 353792 |
| 22 | -2122752 |
| 23 | 5306880 |
| 24 | -7075840 |
| 25 | 5306880 |
| 26 | -2122752 |
| 27 | 353792 |
| 28 | -22368256 |
| 29 | 156577792 |
| 30 | -469733376 |
| 31 | 782888960 |
| 32 | -782888960 |
| 33 | 469733376 |
| 34 | -156577792 |
| 35 | 22368256 |