gistfile1.rb

def first_n_primes(n)
   return [] if n <= 0

   @primes ||= [2]
   x = @primes.last + 1
  
   until @primes.length >= n
      prime = true
      
      @primes.each do |p|
        if x % p == 0
          prime = false
          break
        end
      end
      
      @primes << x if prime
      x += 1
   end
   
   @primes[0..n-1]
end