Step 1: Divide the number into separate digits:
44581 => 4 4 5 8 1
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 4 = 0
4 to 5 = 1
5 to 8 = 3
8 to 1 = 7
1 to 4 = 3
Step 3: Combine the filters to a string:
0 1 3 7 3 = 01373