Complete the recursive formula of the arithmetic sequence 1, 15, 29, 43,...1,15,29,43,...1, comma, 15, comma, 29, comma, 43, 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