a(n)=-a(n-1)+4*a(n-2)+4*a(n-3).

Terms

a(0) =4a(1) =-2a(2) =1a(3) =7a(4) =-11a(5) =43a(6) =-59a(7) =187a(8) =-251a(9) =763a(10) =-1019a(11) =3067a(12) =-4091a(13) =12283a(14) =-16379a(15) =49147a(16) =-65531a(17) =196603a(18) =-262139a(19) =786427a(20) =-1048571a(21) =3145723a(22) =-4194299a(23) =12582907a(24) =-16777211a(25) =50331643a(26) =-67108859a(27) =201326587a(28) =-268435451a(29) =805306363