This CPT code 70336 does not indicate unilateral or bilateral in itself. You can add the modifier 50 to indicate it as a bilateral procedure.
70336 is a CPT Radiology / Diagnostic Radiology procedure code for: Magnetic resonance (eg., proton) imaging, temporomandibular joint(s).
15*7 = 105 142*7 = 994 So the question is equivalent to finding the sum: 105 + 112 + 119 + ... + 994 = 7*(15 + 16 + 17 + ... + 142) = 7*(142*143/2 - 14*15/2) = 7*(10153 - 105) = 7*10048 = 70336