a(0) = 3, a(n+1) = 2*a(n) + periodic sequence of length 2: repeat [-5, 4].

Terms

a(0) =3a(1) =1a(2) =6a(3) =7a(4) =18a(5) =31a(6) =66a(7) =127a(8) =258a(9) =511a(10) =1026a(11) =2047a(12) =4098a(13) =8191a(14) =16386a(15) =32767a(16) =65538a(17) =131071a(18) =262146a(19) =524287a(20) =1048578a(21) =2097151a(22) =4194306a(23) =8388607a(24) =16777218a(25) =33554431a(26) =67108866a(27) =134217727a(28) =268435458a(29) =536870911