Triangle T(n,k) read by rows, giving number of bracelets (turnover necklaces) with n beads of k colors (n >= 1, 1 <= k <= n).
A081720
Triangle T(n,k) read by rows, giving number of bracelets (turnover necklaces) with n beads of k colors (n >= 1, 1 <= k <= n).
Terms
- a(0) =1a(1) =1a(2) =3a(3) =1a(4) =4a(5) =10a(6) =1a(7) =6a(8) =21a(9) =55a(10) =1a(11) =8a(12) =39a(13) =136a(14) =377a(15) =1a(16) =13a(17) =92a(18) =430a(19) =1505a(20) =4291a(21) =1a(22) =18a(23) =198a(24) =1300a(25) =5895a(26) =20646a(27) =60028a(28) =1a(29) =30
External references
- oeis: A081720