Super Primes

The 142nd superprime is 6311, and the last 3 digits are 311 .

Write a function that determines whether an integer is prime. Then, iterate through the integers to check if they are prime, and if their position amongst the primes is prime.

# Python solution: SuperPrimes

# There are many methods to determine if a number is prime
# This function uses the Sieve of Eratosthenes
import math
def isPrime(n):
    if (n==1):
        return False
    elif(n<4):
        return True
    elif(n%2==0):
        return False
    elif(n<9):
        return True
    elif(n%3==0):
        return False
    else:
        r = math.floor(math.sqrt(n))
        f = 5
        while (f<=r):
            if (n%f==0):
                return False
            if (n%(f+2)==0):
                return False
            f+=6
        return True

# This function returns the nth superprime
def findSuperPrime(n):
    numSuperPrimes = 0
    numPrimes = 0
    c = 0

    # Iterate until you find n superprimes
    while (numSuperPrimes < n):
        c += 1

        # if c is prime...
        if isPrime(c):
            numPrimes += 1

            #... and its position within the primes is also prime
            if isPrime(numPrimes):

                # then c is a superprime
                numSuperPrimes += 1
    return c

print findSuperPrime(142)