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 | 11 |
| 4 | -74 |
| 5 | 477 |
| 6 | -804 |
| 7 | -84425 |
| 8 | 3315334 |
| 9 | -102211207 |
| 10 | 3005297956 |
| 11 | -88338323709 |
| 12 | 2627003399164 |
| 13 | -78764141488043 |
| 14 | 2341929797646648 |
| 15 | -66394419743289105 |
| 16 | 1609460569459689286 |
| 17 | -18001777147777896975 |
| 18 | -1625299659961386724524 |
| 19 | 196005371138608184827003 |