$\"\"$

The number of tiles in first row is $\"\"$ .

The number of rows $\"\"$ .

Since each row has two additional tiles

The equations are $\"\"$ , $\"\"$ and $\"\"$ .

Sum of the an infinite arithmetic series : $\"\"$ .

$\"\"$

$\"\"$ tiles are needed to create the mosaic design.

$\"\"$

$\"\"$ tiles are needed to create the mosaic design.