a(n) = Prime(tribonacci(n)).

Terms

a(0) =2a(1) =2a(2) =3a(3) =7a(4) =17a(5) =41a(6) =89a(7) =193a(8) =419a(9) =859a(10) =1759a(11) =3607a(12) =7247a(13) =14551a(14) =28793a(15) =56893a(16) =111863a(17) =218839a(18) =426583a(19) =827851a(20) =1603769a(21) =3097121a(22) =5966629a(23) =11470489a(24) =22004617a(25) =42142883a(26) =80570929a(27) =153802489a(28) =293176621a(29) =558130051