(2n²+n)²+(2n²+n+1)²+···+(2n²+2n)²=(2n²+2n+1)²+···+(2n²+3n)²或写成[2n(n+1)-n]²+[2n(n+1)-(n-1)]²+···+[2n(n+1)]²=[2n(n+1)+1]²...