Let $a_{n}$ denote the number of all $n$ -digit positive integers formed by the digits 0,1 or both such that no consecutive digits in them are $0 .$ Let $b_{n}=$ the number of such $n$ -digit integers ending with digit 1 and $c_{n}=$ the number of such $n$ -digit integers ending with digit $0 .$
Which of the following is correct?