Is the reward for the Fast of David achieved by fasting on Mondays, Wednesdays, Thursdays, and Saturdays, with the intention of observing the Fast of David and fasting on Mondays and Thursdays?

Fasting one day and breaking fast one day is the best form of fasting and the most beloved to Allah. It is the fasting of David, peace be upon him, and there is no better fasting than it, even if one were to fast continuously for several days.