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 | -42 |
| 3 | -385 |
| 4 | 1673 |
| 5 | 20538 |
| 6 | -61439 |
| 7 | -1067801 |
| 8 | 1942710 |
| 9 | 54264959 |
| 10 | -40927831 |
| 11 | -2699910822 |
| 12 | -694447103 |
| 13 | 131601183175 |
| 14 | 165629091222 |
| 15 | -6282828884353 |
| 16 | -14398654354231 |
| 17 | 293459960979066 |
| 18 | 998994024336385 |
| 19 | -13380544063637849 |
| 20 | -62331251256120714 |