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

A320643

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

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =4a(6) =12a(7) =44a(8) =137a(9) =408a(10) =1190a(11) =3416a(12) =9730a(13) =27560a(14) =78148a(15) =221250a(16) =627960a(17) =1784038a(18) =5081154a(19) =14496956a(20) =41455409a(21) =118764600a(22) =340919744a(23) =980315700a(24) =2823696150a(25) =8145853520a(26) =23533759241a(27) =68081765650a(28) =197206716570a(29) =571906256808

External references