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 | 0 |
| 5 | 0 |
| 6 | -6 |
| 7 | 6 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | -11 |
| 12 | 26 |
| 13 | -15 |
| 14 | 0 |
| 15 | 0 |
| 16 | -16 |
| 17 | 82 |
| 18 | -86 |
| 19 | 20 |
| 20 | 0 |
| 21 | -21 |
| 22 | 172 |
| 23 | -316 |
| 24 | 180 |
| 25 | -15 |
| 26 | -26 |
| 27 | 328 |
| 28 | -872 |
| 29 | 790 |
| 30 | -226 |
| 31 | -25 |
| 32 | 538 |
| 33 | -2043 |
| 34 | 2681 |
| 35 | -1310 |
| 36 | 130 |
| 37 | 843 |
| 38 | -4184 |
| 39 | 7426 |
| 40 | -5390 |
| 41 | 1365 |
| 42 | 1158 |
| 43 | -7855 |
| 44 | 18067 |
| 45 | -17705 |
| 46 | 7185 |
| 47 | 798 |
| 48 | -13701 |
| 49 | 39468 |
| 50 | -50030 |