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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | -4 |
| 6 | -1 |
| 7 | 11 |
| 8 | 2 |
| 9 | -35 |
| 10 | -1 |
| 11 | 112 |
| 12 | -9 |
| 13 | -369 |
| 14 | 66 |
| 15 | 1237 |
| 16 | -327 |
| 17 | -4212 |
| 18 | 1433 |
| 19 | 14527 |
| 20 | -5926 |
| 21 | -50659 |
| 22 | 23749 |
| 23 | 178356 |
| 24 | -93427 |
| 25 | -633225 |
| 26 | 363342 |
| 27 | 2264885 |
| 28 | -1402803 |
| 29 | -8154564 |
| 30 | 5390861 |
| 31 | 29534183 |
| 32 | -20655948 |
| 33 | -107538835 |
| 34 | 79005679 |
| 35 | 393462584 |
| 36 | -301884895 |
| 37 | -1445937945 |
| 38 | 1153012596 |
| 39 | 5335046209 |