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) |
|---|---|
| 9 | 1 |
| 10 | -1 |
| 11 | 1 |
| 12 | -2 |
| 13 | 10 |
| 14 | -11 |
| 15 | 12 |
| 16 | -21 |
| 17 | 31 |
| 18 | -13 |
| 19 | 23 |
| 20 | -42 |
| 21 | 42 |
| 22 | -42 |
| 23 | 43 |
| 24 | 22 |
| 25 | -14 |
| 26 | 33 |
| 27 | -126 |
| 28 | 185 |
| 29 | -273 |
| 30 | 406 |
| 31 | -387 |
| 32 | 637 |
| 33 | -945 |
| 34 | 1092 |
| 35 | -1389 |
| 36 | 1841 |
| 37 | -2358 |
| 38 | 2852 |
| 39 | -3023 |
| 40 | 3876 |
| 41 | -4953 |
| 42 | 5593 |
| 43 | -6321 |
| 44 | 7581 |
| 45 | -9222 |
| 46 | 10241 |
| 47 | -11205 |
| 48 | 14021 |
| 49 | -16247 |
| 50 | 17710 |
| 51 | -19858 |
| 52 | 23015 |
| 53 | -26705 |
| 54 | 28908 |
| 55 | -31318 |
| 56 | 36270 |
| 57 | -41316 |
| 58 | 45619 |
| 59 | -49015 |
| 60 | 55287 |