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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 10 |
| 4 | -67 |
| 5 | 626 |
| 6 | -7745 |
| 7 | 117650 |
| 8 | -2097671 |
| 9 | 43046803 |
| 10 | -999990009 |
| 11 | 25937424602 |
| 12 | -743008621115 |
| 13 | 23298085122482 |
| 14 | -793714765724621 |
| 15 | 29192926025441476 |
| 16 | -1152921504875286543 |
| 17 | 48661191875666868482 |
| 18 | -2185911559727678460653 |
| 19 | 104127350297911241532842 |