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 | 1 |
| 5 | 98 |
| 6 | -39 |
| 7 | 3225 |
| 8 | 1226 |
| 9 | 6459 |
| 10 | 12473 |
| 11 | 821830 |
| 12 | -214739887 |
| 13 | -201448561 |
| 14 | -8997850614 |
| 15 | -514986723363 |
| 16 | -1310942141971 |
| 17 | -26465356716946 |
| 18 | -931753364233567 |
| 19 | -1858534483400559 |
| 20 | 167210272584038942 |
| 21 | -7112146717031426801 |
| 22 | 312288595642509829797 |