a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 0, a(1) = 1, a(2) = 0, a(3) = 2.

Terms

a(0) =0a(1) =1a(2) =0a(3) =2a(4) =3a(5) =4a(6) =6a(7) =11a(8) =18a(9) =28a(10) =45a(11) =74a(12) =120a(13) =193a(14) =312a(15) =506a(16) =819a(17) =1324a(18) =2142a(19) =3467a(20) =5610a(21) =9076a(22) =14685a(23) =23762a(24) =38448a(25) =62209a(26) =100656a(27) =162866a(28) =263523a(29) =426388