Dice Game 3

Chef is playing a game consisting of $N$ rounds. In each round he rolls a regular six faced dice. He starts with an initial score of $0$. Let the number rolled by him in a particular round be $X$. If this is not the first round and the previous number rolled was $1$, Chef will add $2 \cdot X$ to his score, otherwise he will add $X$ to his score. For example, if the game has $6$ rounds and the