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 | 80 |
| 4 | -1751 |
| 5 | 53402 |
| 6 | -2088528 |
| 7 | 99680667 |
| 8 | -5617170700 |
| 9 | 365003288652 |
| 10 | -26868393676609 |
| 11 | 2209797209486528 |
| 12 | -200828403704351068 |
| 13 | 19986049281174575497 |
| 14 | -2161617056877509895386 |
| 15 | 252467067400866652634004 |
| 16 | -31668302130310076212791823 |