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 | 2 |
| 3 | -3 |
| 4 | 2 |
| 5 | -9 |
| 6 | 6 |
| 7 | 4 |
| 8 | -36 |
| 9 | 75 |
| 10 | -30 |
| 11 | 4 |
| 12 | -60 |
| 13 | 255 |
| 14 | -330 |
| 15 | 90 |
| 16 | 8 |
| 17 | -180 |
| 18 | 1290 |
| 19 | -3465 |
| 20 | 3150 |
| 21 | -630 |
| 22 | 8 |
| 23 | -252 |
| 24 | 2730 |
| 25 | -12495 |
| 26 | 23940 |
| 27 | -16380 |
| 28 | 2520 |
| 29 | 16 |
| 30 | -672 |
| 31 | 10248 |
| 32 | -71400 |
| 33 | 235305 |
| 34 | -343980 |
| 35 | 185220 |
| 36 | -22680 |
| 37 | 16 |
| 38 | -864 |