Triangular Moving Average   

Triangular moving average place the majority of the weight on the middle portion of the price series. They are actually double-smoothed simple moving averages. The periods used in the simple moving averages varies depending on if you specify an odd or even number of time periods. For example, for a 7 period moving average, the weighting factors are 1, 2, 3, 4, 3, 2, and 1.
Usage:
Moving averages are used to help identify the trend of prices.  By creating an average of prices, that “moves” with the addition of new data, the price action on the security being analyzed is “smoothed”. 
In other words, by calculating the average value of a underlying security or indicator, fluctuations are reduced in importance and what remains is a stronger indication of the trend of prices over the period being analyzed