a(n) = floor(2^n / n^3).

Terms

a(0) =2a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =1a(10) =1a(11) =2a(12) =3a(13) =5a(14) =9a(15) =16a(16) =26a(17) =44a(18) =76a(19) =131a(20) =226a(21) =393a(22) =689a(23) =1213a(24) =2147a(25) =3818a(26) =6818a(27) =12228a(28) =22012a(29) =39768