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 | 6 |
| 2 | -4 |
| 3 | 0 |
| 4 | -16 |
| 5 | -24 |
| 6 | -64 |
| 7 | -120 |
| 8 | -256 |
| 9 | -504 |
| 10 | -1024 |
| 11 | -2040 |
| 12 | -4096 |
| 13 | -8184 |
| 14 | -16384 |
| 15 | -32760 |
| 16 | -65536 |
| 17 | -131064 |
| 18 | -262144 |
| 19 | -524280 |
| 20 | -1048576 |
| 21 | -2097144 |
| 22 | -4194304 |
| 23 | -8388600 |
| 24 | -16777216 |
| 25 | -33554424 |
| 26 | -67108864 |
| 27 | -134217720 |
| 28 | -268435456 |
| 29 | -536870904 |
| 30 | -1073741824 |
| 31 | -2147483640 |