Triangle read by rows: T(n,k) is the number of permutations of 1..n arranged in a circle with exactly k descents.
A334218
Triangle read by rows: T(n,k) is the number of permutations of 1..n arranged in a circle with exactly k descents.
Terms
- a(0) =1a(1) =1a(2) =0a(3) =0a(4) =2a(5) =0a(6) =0a(7) =3a(8) =3a(9) =0a(10) =0a(11) =4a(12) =16a(13) =4a(14) =0a(15) =0a(16) =5a(17) =55a(18) =55a(19) =5a(20) =0a(21) =0a(22) =6a(23) =156a(24) =396a(25) =156a(26) =6a(27) =0a(28) =0a(29) =7
External references
- oeis: A334218