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

Terms

a(0) =1a(1) =1a(2) =4a(3) =9a(4) =26a(5) =70a(6) =197a(7) =553a(8) =1570a(9) =4476a(10) =12827a(11) =36894a(12) =106471a(13) =308113a(14) =893804a(15) =2598313a(16) =7567466a(17) =22076404a(18) =64498427a(19) =188689684a(20) =552675365a(21) =1620567763a(22) =4756614062a(23) =13974168190a(24) =41088418151a(25) =120906613075a(26) =356035078102