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[Guest]

How can I find the longest string of consecutive composite numbers between 1 and 50. What are those numbers?



I need to identify all of the numbers between 1 and 20 that have an odd number of diviosrs. How are the numbers related?

 

[Gene]

Divisors come in pairs (eg 1 & 50, 2 & 25, 5 & 10,...) unless the number is a square. Then there is one un-paired number.