Triangular array read by rows. T(n,k) is the number of ordered pairs of n-permutations with exactly k rise/falls or fall/rises, n >= 0, 0 <= k <= max{0,n-1}.

A362745

Triangular array read by rows. T(n,k) is the number of ordered pairs of n-permutations with exactly k rise/falls or fall/rises, n >= 0, 0 <= k <= max{0,n-1}.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =2a(4) =10a(5) =16a(6) =10a(7) =88a(8) =200a(9) =200a(10) =88a(11) =1216a(12) =3536a(13) =4896a(14) =3536a(15) =1216a(16) =24176a(17) =85872a(18) =149152a(19) =149152a(20) =85872a(21) =24176a(22) =654424a(23) =2743728a(24) =5714472a(25) =7176352a(26) =5714472a(27) =2743728a(28) =654424a(29) =23136128

External references