Find the missing numbers in the sequence by identifying the pattern.<br><br>
&bull; Starting from 3500, the numbers increase by 20 each step.<br>
&bull; After 3520: 3520 + 20 = 3540.<br>
&bull; After 3560: 3560 + 20 = 3580.<br><br>
Final Answer: 3540, 3580