Triangle read by rows: T(n,k) = number of Schroeder (or royal) n-paths (A006318) containing k returns to the diagonal y=x. (A northeast step lying on y=x contributes a return.)

A108891

Triangle read by rows: T(n,k) = number of Schroeder (or royal) n-paths (A006318) containing k returns to the diagonal y=x. (A northeast step lying on y=x contributes a return.)

Terms

    a(0) =2a(1) =2a(2) =4a(3) =6a(4) =8a(5) =8a(6) =22a(7) =28a(8) =24a(9) =16a(10) =90a(11) =112a(12) =96a(13) =64a(14) =32a(15) =394a(16) =484a(17) =416a(18) =288a(19) =160a(20) =64a(21) =1806a(22) =2200a(23) =1896a(24) =1344a(25) =800a(26) =384a(27) =128a(28) =8558a(29) =10364

External references