a(1) = 1; a(n+1) = floor((sum{k=1 to n} a(k)^3)^(1/3)).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =2a(9) =2a(10) =2a(11) =3a(12) =3a(13) =4a(14) =5a(15) =6a(16) =7a(17) =9a(18) =11a(19) =14a(20) =17a(21) =21a(22) =27a(23) =34a(24) =42a(25) =53a(26) =67a(27) =84a(28) =106a(29) =133