Expression 2: Start sum from "n" equals 1 to 100000, end sum, StartFraction, "a" left bracket, mod left parenthesis, "n" minus 1 , length left parenthesis, "a" , right parenthesis , right parenthesis plus 1 , right bracket Over "n" , EndFraction equals 1.1 8 7 4 1 0 4 1 1 8 2100000∑n=1amodn−1,lengtha+1n