[math-fun] tables

Hi - I've just received an email from a reader who saw in a Cologne museum a document called Fundamentalis Tabula Arithmetica from 1638. It is a table of multiples for all the numbers up to 100 and also the tables for these five numbers: 106, 117, 256, 318 and 365 Its pretty obvious why 256 and 365 are included. Might anyone have any thoughts as to why 106, 117 and 318 (3x106) are also included? Alex