Find the rules 6,13,27,49, (), 121, (). How to fill in the brackets?

Find the rules 6,13,27,49, (), 121, (). How to fill in the brackets?

I'll give you a sequence of numbers, and you can see clearly. The second row is the result of subtracting two adjacent numbers in the first row. The third row is the result of subtracting two adjacent numbers in the second row
6 13 27 49 (80) 121 (173 )
7 14 22 31 41 52
7 8 9 10 11