Strange string encoding in C code

[dila]

This is interesting to me because it would lead to a nice key extraction challenge where the output is compared to a fixed string, then the objective is to figure out the list of magic numbers that encode to that string.

For example, if the output is "ninja", then the solution key is {21,19,6,17,12}, as it is in the example code i pasted.

Can anyone derive a set of coefficients that decode to a text string of their choice using the above code?