Step 1: Divide the number into separate digits:
30472 => 3 0 4 7 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
3 to 0 = 3
0 to 4 = 4
4 to 7 = 3
7 to 2 = 5
2 to 3 = 1
Step 3: Combine the filters to a string:
3 4 3 5 1 = 34351