A Google search on the -4-(1/4)” search string can be translated into a contradictory search string. Google is working on a fix for the bug, but some porn sites are still getting results with XXX titles. Google declined to comment on how the bug is coming along, but it’s working with Google to fix it. The bug is likely to be caused by Google calculating the numerical query as it should, but also running it as a normal text search, just in case”]
Source: https://nakedsecurity.sophos.com/2013/02/12/google-search-bug/