What Comes Next in the Sequence: 3, 13, 43, 73, ?? October 30, 2017May 11, 2016 by Bhavini Look at the series of numbers and find the next number. What comes next in the sequence; 3, 13, 43, 73, ?? Share it with your friends on Facebook and WhatsApp. Show Answer The logic to this series is as follows; 2 x 2 – 1 = 4 – 1 = 3; 4 x 4 – 3 = 16 – 3 = 13; 8 x 6 – 5 = 48 – 5 = 43; 10 x 8 – 7 = 80 – 7 = 73; Therefore we can find the answer as; 12 x 10 – 9 = 120 – 9 = 111 Missing next number = 111