Take 1 and divide it by 998001. Go on, do it. If’n yer too lazy, busy or uninterested, the reason why I suggested this after the break.
1/998001 generates all the three-digit numbers from 000 to 999, in order.
1/9801 generates all the two-digit numbers from 00 to 99, in order.
1/99980001 generates all the four-digit numbers from 0000 to 9999.
Go ahead. Ask me why.