from math import sqrt
 def isPrime(n):
  'judge whether a positive integer is a prime number!'
  if n==1:
    return False
  k=int(sqrt(n))
  for i in range(2,k+1):
    if n%i==0:
      return False
  return True
def getMonisen(n):
  count=0
  l=[]
  P=2#最小的素数是2，因此P初值为2
  while True:
    if isPrime(P):
      M=2**P-1
      if isPrime(M):
        l.append(M)
        count+=1
        if count==n:
          break
    P+=1
  return l
l=getMonisen(5)
print l