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 | 20 |
| 3 | -64 |
| 4 | 164 |
| 5 | -392 |
| 6 | 896 |
| 7 | -1920 |
| 8 | 3908 |
| 9 | -7684 |
| 10 | 14632 |
| 11 | -27072 |
| 12 | 48896 |
| 13 | -86408 |
| 14 | 149760 |
| 15 | -255104 |
| 16 | 427652 |
| 17 | -706568 |
| 18 | 1152020 |
| 19 | -1855296 |
| 20 | 2954056 |
| 21 | -4654080 |
| 22 | 7260288 |
| 23 | -11221632 |
| 24 | 17194496 |
| 25 | -26131980 |
| 26 | 39409960 |
| 27 | -59003008 |
| 28 | 87728640 |
| 29 | -129586568 |
| 30 | 190226176 |
| 31 | -277587456 |
| 32 | 402779396 |
| 33 | -581276160 |
| 34 | 834539560 |
| 35 | -1192216320 |