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

Terms

a(0) =1a(1) =0a(2) =2a(3) =1a(4) =3a(5) =3a(6) =6a(7) =7a(8) =12a(9) =16a(10) =25a(11) =35a(12) =53a(13) =76a(14) =113a(15) =164a(16) =242a(17) =353a(18) =519a(19) =759a(20) =1114a(21) =1631a(22) =2392a(23) =3504a(24) =5137a(25) =7527a(26) =11033a(27) =16168a(28) =23697a(29) =34728