On Oct 4, 7:11*am, Guidu wrote:

look at cells A3 A4 and A5, I would like to drag and continuing the
serie...jumping two cells while dragging. or like cells D3, E3 and F3
(esentially the same)

* * * * A * * * B * * * C * * * D * * * E * * * F

1 * * * 2 * * * 1 * * * 8 * * * 2 * * * 6 * * * 8
2 * * * * * * * * * * * * * * * * * * * * * * *
3 * * * 3 * * * (A1+B1) * * * * 3 * * * 10 * * *14
4 * * * 10 * * *(C1+D1) * * * * (A1+B1) (C1+D1) (E1+F1)
5 * * * 14 * * *(E1+F1) * * * * * * * * * * * *
6 * * * * * * * * * * * * * * * * * * * * * * *


Try...

=SUM(OFFSET($A$1:$B$1,0,ROWS($1:1)*2-2))

Ken Johnson