You have a
grid of size
n x 3 and you want to paint each cell of the grid with exactly one of the three colors: Red, Yellow, or Green while making sure that no two adjacent cells have the same color (i.e., no two cells that share vertical or horizontal sides have the same color).
n the number of rows of the grid, return the number of ways you can paint this
grid. As the answer may grow large, the answer must be computed modulo
109 + 7.
Input: n = 1 Output: 12 Explanation: There are 12 possible way to paint the grid as shown.
Input: n = 2 Output: 54
Input: n = 3 Output: 246
Input: n = 7 Output: 106494
Input: n = 5000 Output: 30228214
n == grid.length
grid[i].length == 3
1 <= n <= 5000