Floor(Zeta(3)^n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =3a(6) =3a(7) =4a(8) =5a(9) =6a(10) =7a(11) =9a(12) =10a(13) =13a(14) =15a(15) =19a(16) =22a(17) =27a(18) =33a(19) =39a(20) =47a(21) =57a(22) =68a(23) =82a(24) =99a(25) =119a(26) =143a(27) =172a(28) =207a(29) =249