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 | -6 |
| 3 | 85 |
| 4 | -1490 |
| 5 | 29226 |
| 6 | -614004 |
| 7 | 13511709 |
| 8 | -307448490 |
| 9 | 7174776190 |
| 10 | -170777485556 |
| 11 | 4130050311234 |
| 12 | -101192982385844 |
| 13 | 2506610481299380 |
| 14 | -62668163792277840 |
| 15 | 1579300030107459885 |
| 16 | -40076101342241993370 |