kill(all)$

van=facebook.com/LearningCalculus;

f(n):=(n*(n-1)*(n-2)!*sum(i, i, 1, n))/((n-2)!);

fullratsimp(f(n));

g(n):=(n*(n-1)*(n-2)!*(n/2)*(n+1))/((n-2)!);

fullratsimp(g(n));

limit(%,n,inf);