Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k up-down runs (1 <= k <= n).
A186370
Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k up-down runs (1 <= k <= n).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =2a(6) =1a(7) =7a(8) =11a(9) =5a(10) =1a(11) =15a(12) =43a(13) =45a(14) =16a(15) =1a(16) =31a(17) =148a(18) =268a(19) =211a(20) =61a(21) =1a(22) =63a(23) =480a(24) =1344a(25) =1767a(26) =1113a(27) =272a(28) =1a(29) =127
External references
- oeis: A186370