Binary string recursion

please told me what is happen in this question …bcz i am not understand question …

if n=5 then
example : -10011 is valid or not

if valid why ??

bcz you told me no consecutive ones occur …

please explain this question in detail

hello @vishal_sangal_123

no it is not valid becuase two 1 is consecutive .

u need to generate n bit number such that it does not containt 2 consecutive ones