求出第N个汉明数
汉明数,即任意整数 n = 2^i * 3^j * 5^k ijk为非负整数fun(1) = (0, 0, 0) = 1
fun(2) = (1, 0, 0) = 2
fun(3) = (0, 1, 0) = 3
fun(4) = (2, 0, 0) = 4
fun(5) = (0, 0, 1) = 5
fun(6) = (1, 1, 0) = 6
fun(7) = (3, 0, 0) = 8
fun(8) = (0, 2, 0) = 9
fun(9) = (1, 0, 1) = 10
fun(10) = (2, 1, 0) = 12

[fly]存在即是合理[/fly]