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 | 8 |
| 3 | 40 |
| 4 | 56 |
| 5 | 424 |
| 6 | 248 |
| 7 | 4840 |
| 8 | -1864 |
| 9 | 59944 |
| 10 | -82312 |
| 11 | 801640 |
| 12 | -1789384 |
| 13 | 11409064 |
| 14 | -32881672 |
| 15 | 169790440 |
| 16 | -564370504 |
| 17 | 2601855784 |
| 18 | -9374301832 |
| 19 | 40596571240 |
| 20 | -153088193224 |
| 21 | 640247048104 |
| 22 | -2477305366792 |
| 23 | 10160269944040 |
| 24 | -39887934345544 |
| 25 | 161811173674024 |