For your own personal development, yes, it is worth writing the paper. Ask a local professor to evaluate it and give you feedback on it. It might take a few rewrites before if feels "satisfactory". This is typical for academic writing. 

It can be submitted to a journal, but would only be accepted if it is sufficiently "novel" to appeal to other mathematicians. It is a fairly steep hurdle, but an experienced local professor can advise you there. 

Note, however, that there are some journals dedicated to publishing student work. The need for a "wow" factor is a bit less there so it has a better chance of publication. 

But writing the paper will help you firm and clarify the ideas. Learning, through practice, to be a clear writer in your field is a necessary step and the experience gives you some skill that will be important later. Have fun. Good luck. 

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Note also that almost all work in mathematics and CS is based on earlier work. The exceptions are rare.