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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 1 |
| 12 | -11 |
| 13 | 66 |
| 14 | -286 |
| 15 | 1001 |
| 16 | -3003 |
| 17 | 8008 |
| 18 | -19448 |
| 19 | 43758 |
| 20 | -92378 |
| 21 | 184757 |
| 22 | -352737 |
| 23 | 646877 |
| 24 | -1145837 |
| 25 | 1971882 |
| 26 | -3321890 |
| 27 | 5541965 |
| 28 | -9324315 |
| 29 | 16231215 |
| 30 | -30045015 |
| 31 | 60090031 |
| 32 | -129024511 |
| 33 | 290305576 |
| 34 | -665732936 |
| 35 | 1523150156 |
| 36 | -3431847188 |