How to insert blank rows between data using dynamic array formula?

If you have 5 rows of data with values 1,2,3,4,5, how can a dynamic array formula be used to create 10 rows of data by inserting a blank item after each element. So the results should be an array of 10 rows 1,,2,,3,,4,,5,,.

>Solution :

You could try using EXPAND() function:

=TOCOL(EXPAND(A1:A5,,2,""))

Or,

=TOCOL(EXPAND(A1:A5,,MAX(A1:A5)/2,""))