How to get the sheet name from a cell when using a function such as SUM or ArrayFormula?

Question

I have the following formula:

=ArrayFormula(SUM(Morten!$M4:$M400))

How can I replace Morten with the contents of a cell, ie cell C13, so that ArrayFormula will still work?

Answer 1

Have you tried the Indirect function?

=ArrayFormula(SUM(Indirect(C13&"!M4:M400")))

But why wrap the Sum with an ArrayFormula? Sum already works with a range like that. Well, I'll guess you probably simplified the formula to post, removing the part that made ArrayFormula necessary.