-4/27 + Pi^2*(32/81 - (16*x)/81) + (22*x)/27 + 
 (-40/27 + (16*x)/27)*HPL[{0}, x] + (-64/27 + (16*x)/27)*HPL[{1}, x] + 
 (-64/27 + (32*x)/27)*HPL[{2}, x] + (-16/27 + (8*x)/27)*HPL[{0, 0}, x] + 
 (-64/27 + 64/(27*x) + (32*x)/27)*HPL[{1, 0}, x] + 
 (-128/27 + 128/(27*x) + (64*x)/27)*HPL[{1, 1}, x]
