MathematicsMedium64×since 2002Q3003∑r=120(r2+1)(r!)\sum\limits_{r=1}^{20}\left(r^{2}+1\right)(r !)r=1∑20(r2+1)(r!) is equal toA22!−21!22 !-21 !22!−21!B22!−2(21!)22 !-2(21 !)22!−2(21!)C21!−2(20!)21 !-2(20 !)21!−2(20!)D21!−2021 !-2021!−20 !Check answerSkip