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 | -5 |
| 4 | -11 |
| 5 | 18 |
| 6 | 711 |
| 7 | 10113 |
| 8 | 125042 |
| 9 | 1485627 |
| 10 | 17151083 |
| 11 | 185932580 |
| 12 | 1665928529 |
| 13 | 4570649471 |
| 14 | -349942007986 |
| 15 | -14532197609433 |
| 16 | -433111168649251 |
| 17 | -11579368513540914 |
| 18 | -293948221716443209 |
| 19 | -7208510256850719447 |
| 20 | -170577027262193604678 |
| 21 | -3823168355141657356481 |
| 22 | -76959686241473750407701 |