Triangle T(n,k) read by rows: T(n,k) = the number of ways of seating n people around a table for the second time so that k pairs are maintained. Reflected and rotated sequences are counted as one.
A326411
Triangle T(n,k) read by rows: T(n,k) = the number of ways of seating n people around a table for the second time so that k pairs are maintained. Reflected and rotated sequences are counted as one.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =0a(5) =1a(6) =0a(7) =0a(8) =0a(9) =1a(10) =0a(11) =0a(12) =2a(13) =0a(14) =1a(15) =1a(16) =0a(17) =5a(18) =5a(19) =0a(20) =1a(21) =3a(22) =12a(23) =15a(24) =20a(25) =9a(26) =0a(27) =1a(28) =23a(29) =70
External references
- oeis: A326411