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 | -1 |
| 4 | 1 |
| 5 | 1 |
| 6 | -4 |
| 7 | 3 |
| 8 | 8 |
| 9 | -23 |
| 10 | 10 |
| 11 | 67 |
| 12 | -153 |
| 13 | 9 |
| 14 | 586 |
| 15 | -1081 |
| 16 | -439 |
| 17 | 5249 |
| 18 | -7734 |
| 19 | -7941 |
| 20 | 47501 |
| 21 | -53791 |
| 22 | -105314 |
| 23 | 430119 |
| 24 | -343044 |
| 25 | -1249799 |
| 26 | 3866556 |
| 27 | -1730017 |
| 28 | -13996097 |
| 29 | 34243897 |
| 30 | -1947204 |
| 31 | -150962373 |
| 32 | 296101864 |
| 33 | 121857185 |