Number of identity (asymmetric) bracelets (or necklaces) with n red and blue beads such that the beads switch colors when bracelet is turned over.

A066316

Number of identity (asymmetric) bracelets (or necklaces) with n red and blue beads such that the beads switch colors when bracelet is turned over.

Terms

    a(0) =1a(1) =5a(2) =24a(3) =91a(4) =340a(5) =1224a(6) =4365a(7) =15521a(8) =55311a(9) =197964a(10) =712243a(11) =2577105a(12) =9375360a(13) =34284971a(14) =125977464a(15) =464938189a(16) =1722817415a(17) =6407307543a(18) =23909159417a(19) =89491715105a(20) =335908316844

External references