a(0)=2, a(1)=8, a(n) = a(n-1) + 2*a(n-2).

Terms

a(0) =2a(1) =8a(2) =12a(3) =28a(4) =52a(5) =108a(6) =212a(7) =428a(8) =852a(9) =1708a(10) =3412a(11) =6828a(12) =13652a(13) =27308a(14) =54612a(15) =109228a(16) =218452a(17) =436908a(18) =873812a(19) =1747628a(20) =3495252a(21) =6990508a(22) =13981012a(23) =27962028a(24) =55924052a(25) =111848108a(26) =223696212a(27) =447392428a(28) =894784852a(29) =1789569708