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 | -2 |
| 3 | 2 |
| 4 | -4 |
| 5 | 10 |
| 6 | -6 |
| 7 | -8 |
| 8 | 38 |
| 9 | -54 |
| 10 | 24 |
| 11 | -16 |
| 12 | 130 |
| 13 | -330 |
| 14 | 336 |
| 15 | -120 |
| 16 | -32 |
| 17 | 422 |
| 18 | -1710 |
| 19 | 3000 |
| 20 | -2400 |
| 21 | 720 |
| 22 | -64 |
| 23 | 1330 |
| 24 | -8106 |
| 25 | 21840 |
| 26 | -29400 |
| 27 | 19440 |
| 28 | -5040 |
| 29 | -128 |
| 30 | 4118 |
| 31 | -36414 |
| 32 | 141624 |
| 33 | -285600 |
| 34 | 312480 |
| 35 | -176400 |
| 36 | 40320 |