Complete the sequence

Find the next number that fits the pattern:

169Explanation:Each number is a sum of digits of the previous number squareds(n) = [sum of digits of s(n-1)]^{2}16 = 4^{2}49 = (1+6)^{2} = 7^{2}169 = (4+9)^{2} = 13^{2} Show correct answer