dakl / luhn

Calculate Control digit for all possible 4-digit numbers, disallowing substrings ["09", "90", "22", "55", "33", "66", "44", "77"]

luhn

Calculate Control digit for all possible 4-digit numbers, disallowing certain substrings.

Usage

python luhn.py
#00018
#00026
#00034
#00042
#...

Details

This script generates all possible 4-digit string with added control digit using Luhn's algorithm.

The following two-digit substrings are disallowed (and therefore not printed) since Luhn's algorithm doesn't alter the control digit for these changes.

• 09, 90 (transposition)
• 22, 55
• 33, 66
• 44, 77

The IDs are also available in the file ALLOWED_IDS.txt in this repo for easy access.

License

MIT