Generates a number palindrome starting from 1 to a given length.

number_palindrome

import sys

def horizontal_pyramid(current_value, limit):
    if current_value == limit:
        return str(current_value)

    return str(current_value) + horizontal_pyramid(current_value + 1, limit) + str(current_value)

print(horizontal_pyramid(1, int(sys.argv[1])))

# 1 -> '1'
# 2 -> '121'
# 3 -> '12321'
# ... and so on.