a(2) = a(3) = 1; for n >3, a(n) = largest prime factor of n-th Tribonacci number.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =7a(5) =13a(6) =3a(7) =11a(8) =3a(9) =149a(10) =137a(11) =7a(12) =103a(13) =31a(14) =7a(15) =103a(16) =103a(17) =79a(18) =97a(19) =5501a(20) =3469a(21) =919a(22) =51343a(23) =188869a(24) =853a(25) =1427a(26) =470077a(27) =239a(28) =313a(29) =307