Number of primitive (aperiodic) reversible string structures with n beads using a maximum of five different colors.

A056334

Number of primitive (aperiodic) reversible string structures with n beads using a maximum of five different colors.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =9a(4) =31a(5) =111a(6) =454a(7) =1982a(8) =9130a(9) =43547a(10) =211658a(11) =1041316a(12) =5156641a(13) =25640000a(14) =127773440a(15) =637622320a(16) =3184387573a(17) =15910938734a(18) =79521737938a(19) =397510683092

External references