Triangle read by rows: T(n,k) is the number of paths in the first quadrant from (0,0) to (n,0), consisting of steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0), having k doublerises (i.e., UU's) (0 <= k <= floor(n/2) - 1 for n >= 2).

A132279

Triangle read by rows: T(n,k) is the number of paths in the first quadrant from (0,0) to (n,0), consisting of steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0), having k doublerises (i.e., UU's) (0 <= k <= floor(n/2) - 1 for n >= 2).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =6a(4) =15a(5) =1a(6) =36a(7) =4a(8) =91a(9) =17a(10) =1a(11) =232a(12) =60a(13) =5a(14) =603a(15) =206a(16) =26a(17) =1a(18) =1585a(19) =676a(20) =110a(21) =6a(22) =4213a(23) =2174a(24) =444a(25) =37a(26) =1a(27) =11298a(28) =6868a(29) =1687

External references