Triangle T(n,k) read by rows: T(n,k) = number of ways of seating n people around a table for the second time so that k pairs are maintained. Rotated sequences are counted as one.
A326404
Triangle T(n,k) read by rows: T(n,k) = number of ways of seating n people around a table for the second time so that k pairs are maintained. 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) =2a(10) =0a(11) =0a(12) =4a(13) =0a(14) =2a(15) =2a(16) =0a(17) =10a(18) =10a(19) =0a(20) =2a(21) =6a(22) =24a(23) =30a(24) =40a(25) =18a(26) =0a(27) =2a(28) =46a(29) =140
External references
- oeis: A326404