Number of subwords UHH...HD in all peakless Motzkin paths of length n+3, where U=(1,1), D=(1,-1) and H=(1,0).

A089742

Number of subwords UHH...HD in all peakless Motzkin paths of length n+3, where U=(1,1), D=(1,-1) and H=(1,0).

Terms

    a(0) =1a(1) =3a(2) =7a(3) =17a(4) =41a(5) =99a(6) =242a(7) =596a(8) =1477a(9) =3681a(10) =9215a(11) =23155a(12) =58368a(13) =147530a(14) =373768a(15) =948882a(16) =2413264a(17) =6147414a(18) =15682008a(19) =40056238a(20) =102434119a(21) =262228051a(22) =671945055a(23) =1723350315a(24) =4423518544a(25) =11362907022a(26) =29208834520a(27) =75131251334a(28) =193370093508

External references