Doubt on output pattern

#1

Sir can you explain me the output pattern on this question

#2

Hey @sauravzt7
Output pattern is fibonacci
say a is 0 and b is 1
Now we need to form numbers with no consecutive ones.
So for n=1 we can form 0 or 1 so ans =2
for n=2 we can form 0+(0,1) or 1+(0) = 3
for n=3 we can form 00+(0,1) or 10+(0,1) or 01+(1) =5
and so on
so 2,3,5,8,13,…