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 | 1 |
| 4 | -4 |
| 5 | 14 |
| 6 | -35 |
| 7 | 77 |
| 8 | -161 |
| 9 | 356 |
| 10 | -873 |
| 11 | 2267 |
| 12 | -5787 |
| 13 | 13850 |
| 14 | -30361 |
| 15 | 59934 |
| 16 | -103754 |
| 17 | 147968 |
| 18 | -139049 |
| 19 | -58998 |
| 20 | 730972 |
| 21 | -2430881 |
| 22 | 6333238 |
| 23 | -15548722 |
| 24 | 39845197 |
| 25 | -110775861 |
| 26 | 325257904 |
| 27 | -960503811 |
| 28 | 2756222486 |
| 29 | -7568564555 |
| 30 | 19815541729 |
| 31 | -49548068461 |
| 32 | 118752506024 |