Revert transform of (1 - x - 4x^2 + x^3)/(1 - 6x^2).

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =2a(5) =2a(6) =4a(7) =27a(8) =78a(9) =222a(10) =816a(11) =2736a(12) =8784a(13) =29704a(14) =100408a(15) =334889a(16) =1128036a(17) =3819368a(18) =12912484a(19) =43771606a(20) =148863396a(21) =506943540a(22) =1729339848a(23) =5911769970a(24) =20242876176a(25) =69422168880a(26) =238465602096a(27) =820352668488