1+4=5 2+5=12 3+6=21 8+11=? puzzle answer

I came up with 97

1+4=5

2+5=12

(7+5=12)

3+6=21

(9+12=21)

4+7=33

(11+21=33)

5+8=46

(13+33=46)

6+9=61

(15+46=61)

7+10=78

(17+61=78)

8+11=97

(19+78=97)

The answer is 97. The first expression is 1+4=5. In the next expression, both numbers are increased by 1 while their sum is increased by 7: (1+1) + (4+1) = (5+7). 2+5=12. In the next expression, both numbers are increased by 1 again, but the sum is increased by the next odd number (which is 9) : (2+1) + (5+1) = (12+9). 3+6=21. So, the series will look like this: 1+4=5. 2+5=12. 3+6=21.4+7=33. 5+8=46. 6+9=61. 7+10=78 - 8+11=97.