Trust me, the numbers are all odd numbers less than 32 bits. Could it be that the syntax is "text" instead of a "number"? What I posted is the complete mathematical code that returns this error message. To check if Mathematical was reading the elements as numbers, I tried 2 list5[] and got out: 6854 which was twice the last element, but I am not sure that mathematica always treats the elements as numeric and not just when coupled with multiplication. As for a short list to import, try to import 43,51,59,67,75 and see what output you get.