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

Terms

a(0) =1a(1) =1a(2) =4a(3) =11a(4) =31a(5) =88a(6) =249a(7) =705a(8) =1996a(9) =5651a(10) =15999a(11) =45296a(12) =128241a(13) =363073a(14) =1027924a(15) =2910235a(16) =8239391a(17) =23327176a(18) =66043369a(19) =186980481a(20) =529374876a(21) =1498754083a(22) =4243238399a(23) =12013359840a(24) =34011950561a(25) =96293859201a(26) =272624979364a(27) =771849627691