# How to derive an algorithms that generates check sums [closed]

Column S contains the check sums of the values given in columns R and Xc. Does anyone here have an idea about how to find the corresponding algorithm to calculate the check sums? Thanks in advance

    R    Xc   S
647   72   218
441   47   618
594   67   188
581   55   517
497   58   865
553   65   661
541   52   309


Best regards,

Holzi

• This is a puzzle rather than a well-defined question. – Yuval Filmus Mar 23 '17 at 13:57
• – D.W. Mar 23 '17 at 15:55