Let the smaller odd positive integer be n. Then n(n+2)=255 solve by expanding to quadratic equation n^2+2n-255=0, reject negative root, or by trial and error: sqrt(255)=15.97 =16, so the odd integers should be 15, 17. Check: 15*17=255 ....correct!!!
Alternatively, let the even number sandwiched between the odd integers be x. Then (x+1)(x-1)=255 x^2-1=255 x^2=255+1=256 x=sqrt(256)=16 so the required odd integers are 16-1=15, and 16+1=17.