Complete the recursive formula of the arithmetic sequence -1, -13, -25, -37,...−1,−13,−25,−37,...minus, 1, comma, minus, 13, comma, minus, 25, comma, minus, 37, comma, point, point, point. a(1)=a(1)=a, left parenthesis, 1, right parenthesis, equals a(n)=a(n-1)+a(n)=a(n−1)+a, left parenthesis, n, right parenthesis, equals, a, left parenthesis, n, minus, 1, right parenthesis, plus