a(n) = floor(a(n-1)/3)+a(n-2) with a(0)=2, a(1)=3.

Terms

a(0) =2a(1) =3a(2) =3a(3) =4a(4) =4a(5) =5a(6) =5a(7) =6a(8) =7a(9) =8a(10) =9a(11) =11a(12) =12a(13) =15a(14) =17a(15) =20a(16) =23a(17) =27a(18) =32a(19) =37a(20) =44a(21) =51a(22) =61a(23) =71a(24) =84a(25) =99a(26) =117a(27) =138a(28) =163a(29) =192