Lychrel numbers : Problem 55 Euler Project

Lychrel numbers : Problem 55

If we take 47, reverse and add, 47 + 74 = 121, which is palindromic.
Not all numbers produce palindromes so quickly. For example,

349 + 943 = 1292,
1292 + 2921 = 4213
4213 + 3124 = 7337

That is, 349 took three iterations to arrive at a palindrome.
Although no one has proved it yet, it is thought that some numbers, like 196, never produce a palindrome. A number that never forms a palindrome through the reverse and add process is called a Lychrel number. Due to the theoretical nature of these numbers, and for the purpose of this problem, we shall assume that a number is Lychrel until proven otherwise. In addition you are given that for every number below ten-thousand, it will either (i) become a palindrome in less than fifty iterations, or, (ii) no one, with all the computing power that exists, has managed so far to map it to a palindrome. In fact, 10677 is the first number to be shown to require over fifty iterations before producing a palindrome: 4668731596684224866951378664 (53 iterations, 28-digits).
Surprisingly, there are palindromic numbers that are themselves Lychrel numbers; the first example is 4994.
How many Lychrel numbers are there below ten-thousand?

Problem Source : Euler Project

Python Code


def lychrelNumbers():
    counter = 50
    lychrelCounter = 0
    def reverse(text):
            if len(text) <= 1:
                return text
            return reverse(text[1:]) + text[0]
    for i in range(10000):
        i = i+1
        count = 0
        k = i
        while True:
            s1 = str(k)
            s2 = reverse(s1)
            s3 = str(int(s1)+int(s2))
            if s3 != reverse(s3):
                count = count + 1
            else:
                break   
            k = int(s3)
            if count > counter:
                lychrelCounter = lychrelCounter + 1
                break
    print lychrelCounter
lychrelNumbers()