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) |
|---|---|
| 1 | 1 |
| 2 | -255 |
| 3 | 6562 |
| 4 | -65791 |
| 5 | 390626 |
| 6 | -1673310 |
| 7 | 5764802 |
| 8 | -16843007 |
| 9 | 43053283 |
| 10 | -99609630 |
| 11 | 214358882 |
| 12 | -431720542 |
| 13 | 815730722 |
| 14 | -1470024510 |
| 15 | 2563287812 |
| 16 | -4311810303 |
| 17 | 6975757442 |
| 18 | -10978587165 |
| 19 | 16983563042 |
| 20 | -25699675166 |
| 21 | 37828630724 |
| 22 | -54661514910 |
| 23 | 78310985282 |
| 24 | -110523811934 |
| 25 | 152588281251 |
| 26 | -208011334110 |