Generate the answer to the following sum A(n). The closed form of A(n) is B(n) and thus B(n)=A(n). Express the answer in terms of n. Present the answer in closed form, no intermediate derivations, do all the calculations. (The |.| is the absolute value function.) How much is the sum? A(n)=i=0nj=0n(ij) B(n)=A(n)=X1n2+X2nlgn+X3n+X4, where X1,X2,X3,X4 are integer numbers (thus 1 can be an answer but 1.0 will never be an answer.) Give X1= Give 2= Give X3= Give X4= Example. Let A(n)=2i=1ni. Then B(n)=A(n)=1n2+1n. For that case X1=1,X2=0,X3=1, and X4=0