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 | -9 |
| 2 | -19 |
| 3 | 1971 |
| 4 | 7961 |
| 5 | -1580049 |
| 6 | -9560059 |
| 7 | 2686469931 |
| 8 | 21670511921 |
| 9 | -7838281432089 |
| 10 | -79034002960099 |
| 11 | 34943616861129891 |
| 12 | 422806632973239881 |
| 13 | -220928651974538628129 |
| 14 | -3118693689740162472139 |
| 15 | 1880318896105818396109851 |
| 16 | 30335009203988869812319841 |