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 | -3 |
| 3 | -3 |
| 4 | 665 |
| 5 | -25031 |
| 6 | 607893 |
| 7 | 13065717 |
| 8 | -3684215119 |
| 9 | 322746228337 |
| 10 | -2173907680851 |
| 11 | -5317484317809939 |
| 12 | 1007358319257596489 |
| 13 | 46704901267812186793 |
| 14 | -111828938184578058229947 |
| 15 | 54497429277597236190513381 |
| 16 | -19349766542166780916394521759 |