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 | 36 |
| 3 | -128 |
| 4 | 402 |
| 5 | -1152 |
| 6 | 3064 |
| 7 | -7680 |
| 8 | 18351 |
| 9 | -42112 |
| 10 | 93300 |
| 11 | -200448 |
| 12 | 419150 |
| 13 | -855552 |
| 14 | 1708632 |
| 15 | -3345408 |
| 16 | 6432867 |
| 17 | -12166272 |
| 18 | 22659976 |
| 19 | -41609856 |
| 20 | 75404754 |
| 21 | -134973184 |
| 22 | 238825344 |
| 23 | -418023936 |
| 24 | 724242492 |