Draw the Serpinski Triangle

Question

For today's fractal challenge, draw at least 5 iterations of Sierpinski's triangle! (Shown below is Sierpinski's trinagle)

The resolution of the image must be sufficent that the smallest triangles are at least one pixel in size, and all triangles should be approximately equillateral - pixel art that draws a right-triangle variant will be appreciated, but not accepted. Shortest code in bytes wins!