Triangular array read by rows. T(n,k) is the number of necklaces (turning over is not allowed) of n labeled black or white beads having exactly k black beads.
A219570
Triangular array read by rows. T(n,k) is the number of necklaces (turning over is not allowed) of n labeled black or white beads having exactly k black beads.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =2a(7) =6a(8) =6a(9) =2a(10) =6a(11) =24a(12) =36a(13) =24a(14) =6a(15) =24a(16) =120a(17) =240a(18) =240a(19) =120a(20) =24a(21) =120a(22) =720a(23) =1800a(24) =2400a(25) =1800a(26) =720a(27) =120a(28) =720a(29) =5040
External references
- oeis: A219570