Number of Schroeder paths of length 2n having no UHD, UHHD, UHHHD, ..., where U=(1,1), D=(1,-1), H=(2,0).

A104547

Number of Schroeder paths of length 2n having no UHD, UHHD, UHHHD, ..., where U=(1,1), D=(1,-1), H=(2,0).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =16a(4) =60a(5) =245a(6) =1051a(7) =4660a(8) =21174a(9) =98072a(10) =461330a(11) =2197997a(12) =10585173a(13) =51443379a(14) =251982793a(15) =1242734592a(16) =6165798680a(17) =30754144182a(18) =154123971932a(19) =775669589436

External references