Copy down formula

[Techad]

I would like to customise the copy down formula to increment by 4 eac
time instead of 1. Ex

Row 1 =SUM(A10:A13)
Row 2 + SUM(A14:A17)

etc.

Any ideas?

Many thank

 

[JE McGimpsey]

One way:

=SUM(OFFSET(A$10,(ROW()-1)*4,,4,1))