Step 1: Divide the number into separate digits:
32540 => 3 2 5 4 0
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 2 = 1
2 to 5 = 3
5 to 4 = 1
4 to 0 = 4
0 to 3 = 3
Step 3: Combine the filters to a string:
1 3 1 4 3 = 13143