Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k triple descents (n>=0,0<=k<=n-3). We say that i is a triple descent of a permutation p if p(i) > p(i+1) > p(i+2) > p(i+3).
A220183
Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k triple descents (n>=0,0<=k<=n-3). We say that i is a triple descent of a permutation p if p(i) > p(i+1) > p(i+2) > p(i+3).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =23a(5) =1a(6) =111a(7) =8a(8) =1a(9) =642a(10) =67a(11) =10a(12) =1a(13) =4326a(14) =602a(15) =99a(16) =12a(17) =1a(18) =33333a(19) =5742a(20) =1093a(21) =137a(22) =14a(23) =1a(24) =288901a(25) =59504a(26) =12425a(27) =1852a(28) =181a(29) =16
External references
- oeis: A220183