Finding gaps within rows of numbers

Hello,

Please see attached.

Via macro, I am trying to establish where there is a gap in numbers, signified by a "-". The 2 cases of this are E3 and E5. Note that B7 isn't gap because it is the first numer in the sequence. Nor is L6, as it is the last.

I'd be grateful for some code to generate the TRUE and FALSE values in column A.

Thanks in advance.