Tribonacci numbers: a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = 1, a(2) = 0.

Terms

a(0) =1a(1) =1a(2) =0a(3) =2a(4) =3a(5) =5a(6) =10a(7) =18a(8) =33a(9) =61a(10) =112a(11) =206a(12) =379a(13) =697a(14) =1282a(15) =2358a(16) =4337a(17) =7977a(18) =14672a(19) =26986a(20) =49635a(21) =91293a(22) =167914a(23) =308842a(24) =568049a(25) =1044805a(26) =1921696a(27) =3534550a(28) =6501051a(29) =11957297