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 | 1 |
| 3 | -1 |
| 4 | -1 |
| 5 | 2 |
| 6 | 0 |
| 7 | -4 |
| 8 | 3 |
| 9 | 7 |
| 10 | -12 |
| 11 | -8 |
| 12 | 35 |
| 13 | -6 |
| 14 | -87 |
| 15 | 84 |
| 16 | 172 |
| 17 | -367 |
| 18 | -187 |
| 19 | 1175 |
| 20 | -417 |
| 21 | -3003 |
| 22 | 3621 |
| 23 | 5723 |
| 24 | -15126 |
| 25 | -4374 |
| 26 | 47813 |
| 27 | -26192 |
| 28 | -119731 |
| 29 | 175835 |
| 30 | 211797 |
| 31 | -699210 |
| 32 | -57982 |
| 33 | 2148031 |
| 34 | -1601079 |
| 35 | -5161935 |
| 36 | 9125489 |
| 37 | 8093890 |
| 38 | -34478125 |
| 39 | 3997517 |
| 40 | 101971205 |
| 41 | -97182026 |