a(n) = a(n-2) + a(n-3) + 2*a(n-4), with a(1) = 0, a(2) = 2, a(3) = 3, a(4) = 10.

Terms

a(0) =0a(1) =2a(2) =3a(3) =10a(4) =5a(5) =17a(6) =21a(7) =42a(8) =48a(9) =97a(10) =132a(11) =229a(12) =325a(13) =555a(14) =818a(15) =1338a(16) =2023a(17) =3266a(18) =4997a(19) =7965a(20) =12309a(21) =19494a(22) =30268a(23) =47733a(24) =74380a(25) =116989a(26) =182649a(27) =286835a(28) =448398a(29) =703462