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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 6 |
| 5 | 10 |
| 6 | 14 |
| 7 | 14 |
| 8 | 0 |
| 9 | -48 |
| 10 | -164 |
| 11 | -396 |
| 12 | -792 |
| 13 | -1352 |
| 14 | -1912 |
| 15 | -1912 |
| 16 | 0 |
| 17 | 6528 |
| 18 | 22288 |
| 19 | 53808 |
| 20 | 107616 |
| 21 | 183712 |
| 22 | 259808 |
| 23 | 259808 |
| 24 | 0 |
| 25 | -887040 |
| 26 | -3028544 |
| 27 | -7311552 |
| 28 | -14623104 |
| 29 | -24963200 |
| 30 | -35303296 |
| 31 | -35303296 |
| 32 | 0 |
| 33 | 120532992 |
| 34 | 411525376 |
| 35 | 993510144 |
| 36 | 1987020288 |
| 37 | 3392055808 |
| 38 | 4797091328 |
| 39 | 4797091328 |