genr y=d(x,2)
coef(8) pac
equation eqn1.ls y c y(-1) 
genr pac(1)=@coef(2)
equation eqn2.ls y c y(-1) y(-2) 
genr pac(2)=@coef(3)
equation eqn3.ls y c y(-1) y(-2) y(-3)
genr pac(3)=@coef(4)
equation eqn4.ls y c y(-1) y(-2) y(-3) y(-4)
genr pac(4)=@coef(5)
equation eqn5.ls y c y(-1) y(-2) y(-3) y(-4) y(-5) 
genr pac(5)=@coef(6)
equation eqn6.ls y c y(-1) y(-2) y(-3) y(-4) y(-5) y(-6) 
genr pac(6)=@coef(7)
equation eqn7.ls y c y(-1) y(-2) y(-3) y(-4) y(-5) y(-6) y(-7) 
genr pac(7)=@coef(8)
equation eqn8.ls y c y(-1) y(-2) y(-3) y(-4) y(-5) y(-6) y(-7) y(-8) 
genr pac(8)=@coef(9)

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