Number T(n,k) of permutations of [n] with exactly k occurrences of the consecutive step pattern up, down, down; triangle T(n,k), n>=0, 0<=k<=max(0,floor((n-1)/3)), read by rows.

A242819

Number T(n,k) of permutations of [n] with exactly k occurrences of the consecutive step pattern up, down, down; triangle T(n,k), n>=0, 0<=k<=max(0,floor((n-1)/3)), read by rows.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =6a(4) =21a(5) =3a(6) =90a(7) =30a(8) =450a(9) =270a(10) =2619a(11) =2322a(12) =99a(13) =17334a(14) =20772a(15) =2214a(16) =129114a(17) =195372a(18) =38394a(19) =1067661a(20) =1958337a(21) =591543a(22) =11259a(23) =9713682a(24) =20933154a(25) =8826246a(26) =443718a(27) =96393726a(28) =238789782a(29) =131367258

External references