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 | 0 |
| 4 | 1 |
| 5 | 4 |
| 6 | 9 |
| 7 | 14 |
| 8 | 14 |
| 9 | 0 |
| 10 | -41 |
| 11 | -122 |
| 12 | -243 |
| 13 | -364 |
| 14 | -364 |
| 15 | 0 |
| 16 | 1093 |
| 17 | 3280 |
| 18 | 6561 |
| 19 | 9842 |
| 20 | 9842 |
| 21 | 0 |
| 22 | -29525 |
| 23 | -88574 |
| 24 | -177147 |
| 25 | -265720 |
| 26 | -265720 |
| 27 | 0 |
| 28 | 797161 |
| 29 | 2391484 |
| 30 | 4782969 |
| 31 | 7174454 |
| 32 | 7174454 |
| 33 | 0 |
| 34 | -21523361 |
| 35 | -64570082 |
| 36 | -129140163 |
| 37 | -193710244 |
| 38 | -193710244 |
| 39 | 0 |
| 40 | 581130733 |