https://s0.wp.com/latex.php?latex=%5Cdisplaystyle+16176+%3D400+%5Ctimes+n+%2B400+%5Ctimes+%5Cfrac%7Bn%28n%2B1%29%7D%7B2+%5Ctimes+12%7D+%5Ctimes+%5Cfrac%7B8%7D%7B100%7D+&bg=%23ffffff&fg=%23111111&s=0&c=20201002