sigma= [13.713393005548433, -17.09159674304776, 3.986902527863278, 7.566984305377153, -8.175683095741116]
INPUT=[sigma[x-2:x+1] for x in range(len(sigma)) if x>=2]
numerator=sum(list(map(lambda x:sum(x)**2,INPUT)))
denomerator=sum(list(map(lambda x:x[0]**2+x[1]**2+x[2]**2,INPUT)))
numerator/denomerator