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 | 0 |
| 2 | -1 |
| 3 | 0 |
| 4 | 13 |
| 5 | -20 |
| 6 | 14 |
| 7 | -73 |
| 8 | 373 |
| 9 | -776 |
| 10 | 196 |
| 11 | -223 |
| 12 | 1027 |
| 13 | -1956 |
| 14 | 242 |
| 15 | 139 |
| 16 | -3521 |
| 17 | 2288 |
| 18 | -824 |
| 19 | -36433 |
| 20 | 600283 |
| 21 | -502708 |
| 22 | 83638 |
| 23 | -40071 |
| 24 | 4098793 |
| 25 | 1096584 |
| 26 | -1160948 |
| 27 | 3484553 |
| 28 | -6256069 |
| 29 | 4889852 |
| 30 | -1520674 |
| 31 | -276156781 |