Number of chiral pairs of color patterns (set partitions) in a cycle of length n using exactly 4 colors (subsets).

A320644

Number of chiral pairs of color patterns (set partitions) in a cycle of length n using exactly 4 colors (subsets).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =2a(6) =17a(7) =84a(8) =388a(9) =1586a(10) =6405a(11) =24927a(12) =96404a(13) =368641a(14) =1407515a(15) =5357974a(16) =20403120a(17) =77699323a(18) =296229485a(19) =1130614092a(20) =4321324766a(21) =16539645539a(22) =63397442097a(23) =243352167691a(24) =935420468092

External references