A wall with dimensions $2\times7$ squares has to be covered with ceramic tiles. There are two tiles of ceramic tiles that are available: the $1\times1$ (identical) tile and the $2\times1$ (identical) tile. The $2\times1$ tile can be rotated before being placed on the board. We are provided with as many tiles of each type as we need. In how many ways can we cover the $2\times7$ wall with such tiles?

My idea: consider the cases: have no $2\times1$ tile, have one $2\times1$ tile, have two $2\times1$ tiles, have three $2\times1$ tiles, and so on up to seven $2\times1$ tiles, but that is too complicated and I don't know how to do. Please everyone help me.