One of the great things about two people from any reasonably mature field communicating with each other is that they can take advantage of widely-agreed-upon shorthand. Nearly everyone coming in for a programming interview in 2012 will understand that the '#' character is often used for non-executable program meta-data, that functions are often named with tokens such as 'add1', that 'param:' typically means a function parameter with a description of its value following the colon, what an 'array' is, how subscripts work with them, and what is meant by the terms left-to-right, forward, right-to-left, and backward (regardless of endian-ness, the inclusion of which is sort of humorous since our hypothetical interviewee has, up to this point, been assumed to be completely ignorant of programming-related terms). You go on to suggest defining the problem in terms of short-hand from a more mature, but less specifically relevant field, which I would argue would actually be well understood by fewer potential interviewees.
I do agree with you that it should probably be pointed out that the number of occurrences should be stated as the absolute value of 'n', rather than just 'n', but this would become obvious very quickly when the candidate starts asking clarification questions.