Triangle read by rows: T(n,k) is the number of achiral loops (necklaces or bracelets) of length n using exactly k different colors.

A305540

Triangle read by rows: T(n,k) is the number of achiral loops (necklaces or bracelets) of length n using exactly k different colors.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =4a(7) =3a(8) =1a(9) =6a(10) =6a(11) =1a(12) =10a(13) =21a(14) =12a(15) =1a(16) =14a(17) =36a(18) =24a(19) =1a(20) =22a(21) =93a(22) =132a(23) =60a(24) =1a(25) =30a(26) =150a(27) =240a(28) =120a(29) =1

External references