Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, HD and DU.

A329688

Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, HD and DU.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =1a(5) =2a(6) =4a(7) =2a(8) =5a(9) =10a(10) =5a(11) =14a(12) =28a(13) =14a(14) =42a(15) =84a(16) =42a(17) =132a(18) =264a(19) =132a(20) =429a(21) =858a(22) =429a(23) =1430a(24) =2860a(25) =1430a(26) =4862a(27) =9724a(28) =4862a(29) =16796

External references