Expansion of g.f. (3-4*x-sqrt(1-4*x^2))/(2*(1-2*x)^2).

Terms

a(0) =1a(1) =2a(2) =5a(3) =12a(4) =29a(5) =68a(6) =158a(7) =360a(8) =813a(9) =1812a(10) =4010a(11) =8792a(12) =19170a(13) =41512a(14) =89500a(15) =191952a(16) =410237a(17) =873140a(18) =1853042a(19) =3919608a(20) =8271126a(21) =17406072a(22) =36556580a(23) =76602032a(24) =160240594a(25) =334554248a(26) =697462628a(27) =1451633520a(28) =3017426468a(29) =6263171792