excell reference repitition at regular intervals; : '''
I have two excel sheets(1,2) in a single file, I want the data in sheet 2 is as follows a1(1) a2(2) a3(3) I want to reference this data in sheet1 as follows A2=sheet2!A1, A5=sheet2!A2 , A8=sheet2!A3 and so on, how do I achieve this?

tried entering the sequence 4 times and dragging the formula untill the end. instead of maintaining the sequence, this is what happens;
entered by me;
'''
A2=sheet2!A1 A5=sheet2!A2  A8=sheet2!A3

"on dragging excel automatically enters;"

A11=sheet2!A10  A14=sheet2!A11 A17=sheet2!A12 A20=sheet2!A19 A23=sheet2!A20 A26=sheet2!A21


what i want;

i enter;
A2=sheet2!A1 A5=sheet2!A2  A8=sheet2!A3

excel automatically enters these formulas ;
A11=sheet2!A4  A14=sheet2!A5  A17=sheet2!A6  A20=sheet2!A7  A23=sheet2!A8 A26=sheet2!A9