a(0) = 5, a(1) = 8; for n>1, a(n) = 2*a(n-1) + a(n-2).

Terms

a(0) =5a(1) =8a(2) =21a(3) =50a(4) =121a(5) =292a(6) =705a(7) =1702a(8) =4109a(9) =9920a(10) =23949a(11) =57818a(12) =139585a(13) =336988a(14) =813561a(15) =1964110a(16) =4741781a(17) =11447672a(18) =27637125a(19) =66721922a(20) =161080969a(21) =388883860a(22) =938848689a(23) =2266581238a(24) =5472011165a(25) =13210603568a(26) =31893218301a(27) =76997040170a(28) =185887298641a(29) =448771637452