another possibility:
assuming the 58 in your example is in A34, try this in A35 and drag down
Code:
=IF(B35="","",MAX($A$34:$A34)+1)
don't know where the first number on sheet 2 would be, but something like this in the cell should get the next number
Code:
=MAX(Sheet1!$A$34:$A$500)+1