I'd say there are two possibilities: the trivial choice of p=1 and starting number 4 (so you're summing one consecutive integer starting from 4), or you choose p = 8 and start from -3, so that all numbers from -3 to 3 simplify and you're left with 4 alone:
[tex] -3+(-2)+(-1)+0+1+2+3+4 = 4 [/tex]
