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 | -3 |
| 3 | -12 |
| 4 | 115 |
| 5 | 10801 |
| 6 | 513128 |
| 7 | -31622305 |
| 8 | -29139002795 |
| 9 | -10674262825020 |
| 10 | 8501486817673047 |
| 11 | 49739414341982655313 |
| 12 | 119603027548636893292304 |
| 13 | -1457935338988787721752835601 |
| 14 | -53309412371631686621966575526695 |
| 15 | -722987647385617983636099803915844108 |