Expansion of g.f. (1-4*x+5*x^2)/(1-2*x)^2.

Terms

a(0) =1a(1) =0a(2) =1a(3) =4a(4) =12a(5) =32a(6) =80a(7) =192a(8) =448a(9) =1024a(10) =2304a(11) =5120a(12) =11264a(13) =24576a(14) =53248a(15) =114688a(16) =245760a(17) =524288a(18) =1114112a(19) =2359296a(20) =4980736a(21) =10485760a(22) =22020096a(23) =46137344a(24) =96468992a(25) =201326592a(26) =419430400a(27) =872415232a(28) =1811939328a(29) =3758096384