I'm currently reading a short paragraph here that has the following sentences:
男{おとこ}はそう言{い}うと、もう一枚{いちまい}マントを出{だ}して、急{いそ}いで着{き}ました。北風{きたかぜ}は二{に}枚{まい}のマントを脱{ぬ}がせるために、もっと強{つよ}く風{かぜ}を吹{ふ}きました。
In particular, the first sentence uses the counter directly without の as 一枚{いちまい}マント, while the second uses it with a の as 二{に}枚{まい}のマント.
I checked this answer for particles after counters, but that's for different particles. Looking at this answer that mentions の, it implies it should be either マント一枚{いちまい} or 一枚{いちまい}のマント. And yet, this Tae Kim page on counters has this as an example:
紙{かみ}、二{に}枚{まい}ずつをホッチキスで留{とど}める。
which is without の, but I imagine that's an exception, as ずつ is a suffix and not a noun, and would perhaps be shuffled around into something like this:
二{に}枚{まい}の紙{かみ}ずつをホッチキスで留{とど}める。
However, I'm not too sure then if the original article's lack of の is a typo or if there's a slightly different meaning like the suffix.