Satisfies the tribonacci recurrence: a(n) = a(n-1) + a(n-2) + a(n-3).

Terms

a(0) =0a(1) =1a(2) =3a(3) =4a(4) =7a(5) =13a(6) =24a(7) =44a(8) =81a(9) =149a(10) =274a(11) =504a(12) =927a(13) =1705a(14) =3136a(15) =5768a(16) =10609a(17) =19513a(18) =35890a(19) =66012a(20) =121415a(21) =223317a(22) =410744a(23) =755476a(24) =1389537a(25) =2555757a(26) =4700770a(27) =8646064a(28) =15902591a(29) =29249425