Copy formula horizontally- cell addresses should be vertically

Hi folks.

I have a formula in cell A1 e.g.:
=A2+B2

I would like to copy this formula to cells B1, C1, D1, ... but with formula
=A3+B3
=A4+B4
=A5+B5
=A6+B6

Does exist faster way how to do it (instead manually typing formula)?
Regards
Jan

Is that the 'Actual' formula, or simplified?

For this type of request, please post your 'real' formula.
Solutions to this type of issue are usually not easily 'transcribed' from simplified version to real version.

For Your example, in A1 then drag across
=SUM(OFFSET($A$2:$B$2,COLUMNS($A$1:A1)-COLUMN($A$1),))