Answer:
first_octet = int(input("Enter the first octet: "))
second_octet = int(input("Enter the second octet: "))
third_octet = int(input("Enter the third octet: "))
forth_octet = int(input("Enter the forth octet: "))
octet_start = forth_octet + 1
octet_end = forth_octet + 6
if (1 <= first_octet <= 255) and (0 <= second_octet <= 255) and (0 <= third_octet <= 255) and (0 <= forth_octet <= 255):
    for ip in range(octet_start, octet_end):
        forth_octet = forth_octet + 1
        if forth_octet > 255:
            forth_octet = (forth_octet % 255) - 1
            third_octet = third_octet + 1
            if third_octet > 255:
                third_octet = (third_octet % 255) - 1
                second_octet = second_octet + 1
                if second_octet > 255:
                    second_octet = (second_octet % 255) - 1
                    first_octet = first_octet + 1
                    if first_octet > 255:
                        print("No more available IP!")
                        break
        print(str(first_octet) + "." + str(second_octet) + "." + str(third_octet) + "." + str(forth_octet))
else:
    print("Invalid input!")
Explanation:
- Ask the user for the octets
- Initialize the start and end points of the loop, since we will be printing next 5 IP range is set accordingly
- Check if the octets meet the restrictions
- Inside the loop, increase the forth octet by 1 on each iteration
- Check if octets reach the limit - 255, if they are greater than 255, calculate the mod and subtract 1. Then increase the previous octet by 1. 
For example, if the input is: 1. 1. 20. 255, next ones will be:
1. 1. 21. 0
1. 1. 21. 1
1. 1. 21. 2
1. 1. 21. 3
1. 1. 21. 4
There is an exception for the first octet, if it reaches 255 and others also reach 255, this means there are no IP available.
- Print the result