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 | -2 |
| 5 | 5 |
| 6 | -14 |
| 7 | 39 |
| 8 | -102 |
| 9 | 247 |
| 10 | -558 |
| 11 | 1197 |
| 12 | -2494 |
| 13 | 5167 |
| 14 | -10850 |
| 15 | 23311 |
| 16 | -51132 |
| 17 | 113333 |
| 18 | -250694 |
| 19 | 547871 |
| 20 | -1175998 |
| 21 | 2475153 |
| 22 | -5117486 |
| 23 | 10439895 |
| 24 | -21142030 |
| 25 | 42777735 |
| 26 | -86960284 |
| 27 | 178221401 |
| 28 | -368541508 |
| 29 | 767762191 |
| 30 | -1606535062 |
| 31 | 3365499467 |
| 32 | -7038925364 |
| 33 | 14671422797 |
| 34 | -30450115592 |