41^2=(40+1)^2=40^2+2*40*1+1^2=1600+80+1=1681
91^2=(90+1)^2=90^2+1+2*90=8100+180+1=8281
201^2=(200+1)^2=200^2+1+2*200=40000+400+1=40401
32^2=(30+2)^2=30^2+2*2*30+4=900+120+4=1024
72^2=(70+2)^2=70^2+2*2*70+4=4900+280+4=5184
302^2=(300+2)^2=90000+1200+4=91204