Step 1: Divide the number into separate digits:
40262 => 4 0 2 6 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 0 = 4
0 to 2 = 2
2 to 6 = 4
6 to 2 = 4
2 to 4 = 2
Step 3: Combine the filters to a string:
4 2 4 4 2 = 42442