The New York City Board of Elections has disqualified three independent candidates for Mayor, because their petitions were obviously deficient on their face. Generally this is because the total number of signatures on their petition was a smaller number than the legal requirement of 3,750 signatures. The three that have been removed are William Melisky, Walter Iwuachiw, and Jimmy McMillan. McMillan has challenged his removal in court.
There may be other candidates removed if anyone challenges their petitions and the challenge succeeds. Nevertheless, it seems likely that there will be a record number of candidates for Mayor on the November ballot. Here is a link to the blog post of September 3, which named all the candidates who filed.