Number of primitive (period n) n-bead necklace structures using a maximum of four different colored beads.

A056300

Number of primitive (period n) n-bead necklace structures using a maximum of four different colored beads.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =10a(5) =35a(6) =102a(7) =360a(8) =1232a(9) =4427a(10) =15934a(11) =58465a(12) =215250a(13) =799593a(14) =2983204a(15) =11187200a(16) =42109450a(17) =159081482a(18) =602809326a(19) =2290679807a(20) =8726308212a(21) =33318645341a(22) =127479700198a(23) =488672244040

External references