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 | -4 |
| 2 | 16 |
| 3 | -48 |
| 4 | 128 |
| 5 | -312 |
| 6 | 704 |
| 7 | -1504 |
| 8 | 3072 |
| 9 | -6036 |
| 10 | 11488 |
| 11 | -21264 |
| 12 | 38400 |
| 13 | -67864 |
| 14 | 117632 |
| 15 | -200352 |
| 16 | 335872 |
| 17 | -554952 |
| 18 | 904784 |
| 19 | -1457136 |
| 20 | 2320128 |
| 21 | -3655296 |
| 22 | 5702208 |
| 23 | -8813472 |
| 24 | 13504512 |
| 25 | -20523996 |
| 26 | 30952544 |
| 27 | -46340832 |
| 28 | 68901888 |
| 29 | -101777112 |
| 30 | 149403264 |
| 31 | -218016640 |