Triangle read by rows, T(n,k) with n,k > 1, is the number of subsequences of length k over all permutations of [n], which are neither increasing or decreasing.
A373766
Triangle read by rows, T(n,k) with n,k > 1, is the number of subsequences of length k over all permutations of [n], which are neither increasing or decreasing.
Terms
- a(0) =0a(1) =0a(2) =4a(3) =0a(4) =64a(5) =22a(6) =0a(7) =800a(8) =550a(9) =118a(10) =0a(11) =9600a(12) =9900a(13) =4248a(14) =718a(15) =0a(16) =117600a(17) =161700a(18) =104076a(19) =35182a(20) =5038a(21) =0a(22) =1505280a(23) =2587200a(24) =2220288a(25) =1125824a(26) =322432a(27) =40318a(28) =0a(29) =20321280
External references
- oeis: A373766