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

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =22a(5) =90a(6) =394a(7) =1806a(8) =8558a(9) =41586a(10) =206098a(11) =1037718a(12) =5293446a(13) =27297738a(14) =142078746a(15) =745387038a(16) =3937603038a(17) =20927156706a(18) =111818026018a(19) =600318853926