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RJLiberator
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Homework Statement
Let E denote the set of positive even integers. An element p ∈ E is called an E-prime if p cannot be written as a product of two elements of E. Determine a simple criteria for when elements of E can be uniquely factored into a product of E-primes.
Homework Equations
Some E-primes from my understanding: 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 50
Some terms that can be uniquely factored into e-primes: 4, 12, 20, 28, 44, 52
The Attempt at a Solution
I've spent much more time on this problem then I should have.
I can clearly see that all terms that can be uniquely factored into e-primes must be divisible by 4.
It seems like there is a common ratio of 8 between terms until we get to terms 36 and 60. 36 can be factored into 6*6 and 18*2 while 60 can be factored into 6*10 and 30*2. So these are clearly not unique.
All the terms that can be uniquely factored can not be divisible by 8, that makes sense since 8 = 4*2.
But beyond this, I don't really know what it means by criteria? Should I spit out an equation like 4+8n for n=all integers except 4,7,10,13,...