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 | 0 |
| 2 | -2047 |
| 3 | -177146 |
| 4 | -4194303 |
| 5 | -48828124 |
| 6 | -362797055 |
| 7 | -1977326742 |
| 8 | -8589934591 |
| 9 | -31381059608 |
| 10 | -99999999999 |
| 11 | -285311670610 |
| 12 | -743008370687 |
| 13 | -1792160394036 |
| 14 | -4049565169663 |
| 15 | -8649755859374 |
| 16 | -17592186044415 |