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 | -7 |
| 2 | -21 |
| 3 | 917 |
| 4 | 11571 |
| 5 | -452347 |
| 6 | -13308141 |
| 7 | 435327557 |
| 8 | 25765086291 |
| 9 | -624624700987 |
| 10 | -74611975175661 |
| 11 | 990632591644997 |
| 12 | 299140108182963411 |
| 13 | 249897499717445573 |
| 14 | -1569672873030414985581 |
| 15 | -30079222140754781400763 |