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 | -7 |
| 3 | -119 |
| 4 | 4241 |
| 5 | 216241 |
| 6 | -16578871 |
| 7 | -1851684743 |
| 8 | 236706675617 |
| 9 | 48609995386849 |
| 10 | -8951725537756135 |
| 11 | -3042019551814333463 |
| 12 | 738962020041708730673 |
| 13 | 387782426903449423831441 |
| 14 | -116858640965630479825258519 |
| 15 | -90328812874963081877073927719 |