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 | -1 |
| 2 | -2 |
| 3 | 1 |
| 4 | 23 |
| 5 | 78 |
| 6 | -101 |
| 7 | -2837 |
| 8 | -16388 |
| 9 | -6045 |
| 10 | 814731 |
| 11 | 8464784 |
| 12 | 33033549 |
| 13 | -310826557 |
| 14 | -7037215394 |
| 15 | -63006436867 |
| 16 | -89668812445 |
| 17 | 6772991607814 |
| 18 | 122867563251423 |
| 19 | 1051303604754527 |
| 20 | -1882817550826828 |
| 21 | -228497075285662201 |
| 22 | -4133128828646120841 |
| 23 | -36299819546242627536 |