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 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | -3 |
| 5 | 1 |
| 6 | -1 |
| 7 | 3 |
| 8 | 3 |
| 9 | 0 |
| 10 | -12 |
| 11 | 15 |
| 12 | -20 |
| 13 | 5 |
| 14 | 53 |
| 15 | -113 |
| 16 | 180 |
| 17 | -241 |
| 18 | 153 |
| 19 | 173 |
| 20 | -652 |
| 21 | 787 |
| 22 | 628 |
| 23 | -4801 |
| 24 | 11635 |
| 25 | -18699 |
| 26 | 20775 |
| 27 | -12315 |
| 28 | -6109 |
| 29 | 21253 |
| 30 | -7015 |
| 31 | -61060 |
| 32 | 174382 |
| 33 | -260676 |
| 34 | 190623 |
| 35 | 130141 |
| 36 | -549572 |
| 37 | 399845 |
| 38 | 1577502 |
| 39 | -6670524 |
| 40 | 14603574 |
| 41 | -21111528 |
| 42 | 16110192 |
| 43 | 14794188 |
| 44 | -82586174 |