Step 1: Divide the number into separate digits:
71001 => 7 1 0 0 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
7 to 1 = 6
1 to 0 = 1
0 to 0 = 0
0 to 1 = 1
1 to 7 = 6
Step 3: Combine the filters to a string:
6 1 0 1 6 = 61016