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

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =10a(5) =26a(6) =73a(7) =211a(8) =630a(9) =1918a(10) =5944a(11) =18668a(12) =59311a(13) =190243a(14) =615269a(15) =2004025a(16) =6568174a(17) =21645438a(18) =71681152a(19) =238416580a(20) =796107464a(21) =2667768904a(22) =8968626418a(23) =30240087086a(24) =102238147891a(25) =346514952331