Can anyone figure out a simple expression for the following series of terms (n starting at 0 or 1)? I would like to express as a summation of terms.

x, 2-x, 2+x, 4-x, 4+x, 6-x, 6+x, .

? I can't think of one. Obviously I could break it into two summations but that becomes cumbersome.

Cyberbeer to whoever comes up with something.