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 | 0 |
| 3 | 1 |
| 4 | -2 |
| 5 | 0 |
| 6 | 0 |
| 7 | -16 |
| 8 | 36 |
| 9 | 0 |
| 10 | 0 |
| 11 | 99 |
| 12 | -272 |
| 13 | 0 |
| 14 | 0 |
| 15 | -240 |
| 16 | 1056 |
| 17 | 0 |
| 18 | 0 |
| 19 | -253 |
| 20 | -1800 |
| 21 | 0 |
| 22 | 0 |
| 23 | 2736 |
| 24 | -1464 |
| 25 | 0 |
| 26 | 0 |
| 27 | -4284 |
| 28 | 12544 |
| 29 | 0 |
| 30 | 0 |
| 31 | -6816 |
| 32 | -19008 |
| 33 | 0 |
| 34 | 0 |
| 35 | 27270 |
| 36 | -4554 |
| 37 | 0 |
| 38 | 0 |
| 39 | -6864 |
| 40 | 39880 |
| 41 | 0 |
| 42 | 0 |
| 43 | -66013 |
| 44 | -26928 |
| 45 | 0 |
| 46 | 0 |
| 47 | 44064 |
| 48 | 12544 |
| 49 | 0 |
| 50 | 0 |