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 | -2 |
| 2 | -10 |
| 3 | -39 |
| 4 | -168 |
| 5 | -855 |
| 6 | -5148 |
| 7 | -36057 |
| 8 | -288480 |
| 9 | -2596347 |
| 10 | -25963500 |
| 11 | -285598533 |
| 12 | -3427182432 |
| 13 | -44553371655 |
| 14 | -623747203212 |
| 15 | -9356208048225 |
| 16 | -149699328771648 |
| 17 | -2544888589118067 |
| 18 | -45807994604125260 |