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
3,13,43,73,103
Ans: (3*3)+4=13 (3*13)+4=43 (3*23)+4=73 (3*33)+4=103