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 | 0 |
| 2 | -2 |
| 3 | -9 |
| 4 | -40 |
| 5 | -205 |
| 6 | -1236 |
| 7 | -8659 |
| 8 | -69280 |
| 9 | -623529 |
| 10 | -6235300 |
| 11 | -68588311 |
| 12 | -823059744 |
| 13 | -10699776685 |
| 14 | -149796873604 |
| 15 | -2246953104075 |
| 16 | -35951249665216 |
| 17 | -611171244308689 |
| 18 | -11001082397556420 |
| 19 | -209020565553571999 |