a(n) = 2^n for n = 0..4; for n > 4, a(n) = 2*a(n-1) + a(n-5).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =16a(5) =33a(6) =68a(7) =140a(8) =288a(9) =592a(10) =1217a(11) =2502a(12) =5144a(13) =10576a(14) =21744a(15) =44705a(16) =91912a(17) =188968a(18) =388512a(19) =798768a(20) =1642241a(21) =3376394a(22) =6941756a(23) =14272024a(24) =29342816a(25) =60327873a(26) =124032140a(27) =255006036a(28) =524284096a(29) =1077911008