There is a sequence: 1 / 1,2 / 1,1 / 2,3 / 1,2 / 2,1 / 3,4 / 1,3 / 2,2 / 3,1 / 4 What is the column 7 / 19?

There is a sequence: 1 / 1,2 / 1,1 / 2,3 / 1,2 / 2,1 / 3,4 / 1,3 / 2,2 / 3,1 / 4 What is the column 7 / 19?

grouping,
The first group, 1 / 1, a number, the sum of numerator and denominator is 2;
The second group, 2 / 1,1 / 2, two numbers, the sum of numerator and denominator is 3;
The third group, 3 / 1,2 / 2,1 / 3, three numbers, the sum of numerator and denominator is 4;
The fourth group, 4 / 1,3 / 2,2 / 3,1 / 4, four numbers, the sum of numerator and denominator is 5;
……
7 + 19 = 26, so it's the seventh in group 25
The first 24 groups were divided into four groups
1+2+3+…… +24 = 300
So, 7 / 19 is the number one
300 + 7 = 307