Number of Dyck paths of semilength n such that both consecutive patterns of Dyck paths of semilength 2 occur at least once.

A243965

Number of Dyck paths of semilength n such that both consecutive patterns of Dyck paths of semilength 2 occur at least once.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =10a(6) =44a(7) =179a(8) =702a(9) =2701a(10) =10278a(11) =38866a(12) =146450a(13) =550817a(14) =2070116a(15) =7779655a(16) =29248932a(17) =110047905a(18) =414446256a(19) =1562538171a(20) =5898049688a(21) =22290789562a(22) =84351810044a(23) =319609669957

External references