a(n+5) = a(n+4)+a(n+3)+a(n+2)+a(n+1)+2*a(n) with a(0)=0, a(1)=a(2)=a(3)=a(4)=1.

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =4a(6) =9a(7) =17a(8) =33a(9) =65a(10) =132a(11) =265a(12) =529a(13) =1057a(14) =2113a(15) =4228a(16) =8457a(17) =16913a(18) =33825a(19) =67649a(20) =135300a(21) =270601a(22) =541201a(23) =1082401a(24) =2164801a(25) =4329604a(26) =8659209a(27) =17318417a(28) =34636833a(29) =69273665