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 | -8 |
| 2 | 48 |
| 3 | -224 |
| 4 | 864 |
| 5 | -2928 |
| 6 | 9024 |
| 7 | -25792 |
| 8 | 69312 |
| 9 | -176936 |
| 10 | 432288 |
| 11 | -1016736 |
| 12 | 2312832 |
| 13 | -5107504 |
| 14 | 10983552 |
| 15 | -23060544 |
| 16 | 47373696 |
| 17 | -95401872 |
| 18 | 188637936 |
| 19 | -366744160 |
| 20 | 701930304 |
| 21 | -1324016896 |
| 22 | 2463662016 |
| 23 | -4526174784 |
| 24 | 8216376576 |
| 25 | -14747939768 |
| 26 | 26191413024 |
| 27 | -46048199360 |