I entered this as an array formula.

{=SUM(OFFSET(M2,{0,1,2},0))}

I thought that it would be equivalent to

=SUM((OFFSET(M2,0,0,3,1)))

And equivalent, of course, to:

=SUM(M2:M4)

But, the array formula always returns the first value, i.e. the value in M2.

Can somebody explain why the array formula does not sum the values M2, M3, M4?

(Of course this is a reduced, clearer question, of a more complex situation I have).

Thanks!

Tom