Expansion of (3(1-x)-sqrt(1+6x-7x^2))/(2(1-x)(1-2x)).

Terms

a(0) =1a(1) =0a(2) =2a(3) =-6a(4) =30a(5) =-150a(6) =806a(7) =-4494a(8) =25822a(9) =-151782a(10) =908502a(11) =-5518590a(12) =33933774a(13) =-210814422a(14) =1321230150a(15) =-8343458286a(16) =53037407166a(17) =-339111023046