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

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =10a(7) =18a(8) =31a(9) =55a(10) =96a(11) =169a(12) =296a(13) =520a(14) =912a(15) =1601a(16) =2809a(17) =4930a(18) =8651a(19) =15182a(20) =26642a(21) =46754a(22) =82047a(23) =143983a(24) =252672a(25) =443409a(26) =778128a(27) =1365520a(28) =2396320a(29) =4205249