What is the "asymmetric weights for end series" in a 5-term Henderson filter?
I am trying to seasonally adjust a quarterly data series using the above example, which uses a 13-term Henderson filter aprox half way of the process. However I was unable to proceed since I do not know the values of an asymmetric weights for 5-term Henderson filter, unable to replace the 12-by-6 matrix in the example with a 4-by-2 matrix.
Does anybody know the values of the asymmetric weight for end series in a 5-term Henderson filter?
Note: I did get the stmmetric weights for 5-term Henderson filter (-0.073, 0.294, 0.558, 0.294, -0.073).