The square of natural number is arranged into 1492625364964 in order from small to large

The square of natural number is arranged into 1492625364964 in order from small to large

√10 = 3.xxx
√100 = 10
√1000 = 31.xxxx
√10000 = 100
That is to say, if the square is 1, there will be 1-3
There are four to nine in two
Of the three, 10-31
The 4-bit ones are 32-99
The 5-digit range is 100-316
612 - 3 - (9-4+1)*2 - (31-10+1)*3 - (99-32+1)*4= 259
259÷5 = 51…… Yu 4
Then the number at position 612 is the fourth digit of the square of the 52nd number from 100 (from high to low)
151*151= 22801
The number in position 612 is 0