Now, around it you can place 6 saucers, such that they touch each other. So, 3 times the diameter = 1+6 = 7 saucers. And, these can be surrounded by 12 saucers. So, for 5 times the diameter, 7+12 = 19 saucers. Similarly, you can continue the calculations to get the final answer as

1 + 6 + 12 + 24 + 48 + 96 + 192 + 384 = 763