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

Terms

a(0) =1a(1) =3a(2) =9a(3) =27a(4) =79a(5) =231a(6) =675a(7) =1971a(8) =5755a(9) =16803a(10) =49059a(11) =143235a(12) =418195a(13) =1220979a(14) =3564819a(15) =10407987a(16) =30387571a(17) =88720755a(18) =259032627a(19) =756281907a(20) =2208070579a(21) =6446770227a(22) =18822245427a(23) =54954172467a(24) =160446376243a(25) =468445588275