
先估算这个数小于3的50次方

            
            
              javascript
              
              
            
          
          cnt=0
for i in range(50):
    for j in range(50):
        for k in range(50):
            a=3**i
            b=5**j
            c=7**k
            if a*b*c<=59084709587505:
                cnt+=1
print(cnt-1)#当ijk都为0时,a*b*c=1不是幸运数字所以要减去