Σειριακός αριθμός - συντελεστής ασφαλείας

[johnk1983]

Στο βιβλίο της Leuctturm: Catalogue Euro 2017 γράφει τα παρακάτω στην σελίδα 583:
Calculating the check digit of the first-series banknotes:

Example:  serial number X04875637034
1. The first ten figures of the serial number make up the checksum. 0+4+8+7+5+6+3+7+0+3=43
2. The letter of the country code is replaced by the number of the letter's position in alphabet and this added to the checksum found in step 1. X=24, 24+43=67
3. The result found in step 2 is subtracted from 124. The new figure is divided by 9 and the first figure behind the decimal point taken. 124-67=57, 57./.9=6,33.
4. When 1 is added to the figure derived in step 3 the verification number is derived. 3+1=4, serial number X04875637