Related to the minimal number of periodic orbits of periods guaranteed by Sharkovskii's theorem.

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =0a(5) =2a(6) =0a(7) =3a(8) =0a(9) =6a(10) =1a(11) =9a(12) =2a(13) =18a(14) =4a(15) =30a(16) =8a(17) =56a(18) =16a(19) =99a(20) =32a(21) =186a(22) =64a(23) =337a(24) =128a(25) =635a(26) =256a(27) =1177a(28) =512a(29) =2220