Source code in the crystal programming language

def semiprime(n)
  nf = 0
  (2..n).each do |i|
    while n % i == 0
      return false if nf == 2
      nf += 1
      n  /= i
    end
  end
  nf == 2
end

(1675..1681).each { |n| puts "#{n} -> #{semiprime(n)}" }


def semiprime(n)
  `factor #{n}`.split(' ').size == 3
end
n = 0xffffffffffffffff_u64 # 2**64 - 1 = 18446744073709551615
(n-50..n).each { |n| puts "#{n} -> #{semiprime(n)}" }