Maths script -- 2

I need a maths script developed. Make responsive PHP please. Version 1. Basically the script will ask for 2 parameters. I'll enter in text box R and F e.g R = 2 and F = 1 Then press RUN button to run the script. The output will show all permutations of R and F E.g RRF RFR FRR It will also assign a value to each which we will call the k value. To calculate the k value we need to apply rule. Start from left if we have R we apply map 3x + 1 / 2 If we see F we apply map x / 2 We do this for each permutation and we get an answer of form ax + k / cwe have two columns the permutation and k value Eg RRF 5 RFR. 7 FFR. 10 This is version 1. We will do other versions in successful completion of this