Thursday Code Puzzler:Perfect Numbers
Thursday is code puzzler day here at DZone. The idea is simple: solve the coding problem as efficiently as you can, in any language or framework that you find suitable.
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Find The First 20 Perfect Numbers
The definition of a perfect number, from Wikipedia, states:
In number theory, a perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself (also known as its aliquot sum). Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself) i.e. σ1(n) = 2n.
So, the first perfect number is 6, since 1+2+3 = 6.
With this information, your task is to write a method that will find the first 20 perfect numbers.
Catch up on all our previous puzzlers here.