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 | -1 |
| 3 | 7 |
| 4 | -17 |
| 5 | 23 |
| 6 | -1 |
| 7 | -89 |
| 8 | 271 |
| 9 | -457 |
| 10 | 287 |
| 11 | 967 |
| 12 | -4049 |
| 13 | 8279 |
| 14 | -8641 |
| 15 | -7193 |
| 16 | 56143 |
| 17 | -139657 |
| 18 | 194399 |
| 19 | -24569 |
| 20 | -703889 |
| 21 | 2209943 |
| 22 | -3814273 |
| 23 | 2603047 |
| 24 | 7447951 |
| 25 | -32756041 |
| 26 | 68476319 |
| 27 | -74404793 |
| 28 | -50690897 |
| 29 | 449691863 |
| 30 | -1146312001 |
| 31 | 1640168551 |
| 32 | -335257649 |
| 33 | -5554901257 |