Number of primitive (period n) bracelet structures using exactly four different colored beads.

A056368

Number of primitive (period n) bracelet structures using exactly four different colored beads.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =11a(6) =33a(7) =136a(8) =478a(9) =1849a(10) =6845a(11) =26136a(12) =98406a(13) =373977a(14) =1416249a(15) =5380770a(16) =20440250a(17) =77794939a(18) =296384565a(19) =1131009781a(20) =4321964735a(21) =16541268223a(22) =63400061153a(23) =243358777620a(24) =935431121460

External references