Number of chiral pairs of color patterns (set partitions) in a cycle of length n using 3 or fewer colors (subsets).

A320743

Number of chiral pairs of color patterns (set partitions) in a cycle of length n using 3 or fewer colors (subsets).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =4a(6) =13a(7) =46a(8) =144a(9) =420a(10) =1221a(11) =3474a(12) =9856a(13) =27794a(14) =78632a(15) =222156a(16) =629760a(17) =1787440a(18) =5087797a(19) =14509580a(20) =41479867a(21) =118811286a(22) =341009901a(23) =980488510a(24) =2824029648a(25) =8146494860a(26) =23534997912a(27) =68084154502a(28) =197211336576a(29) =571915188840

External references