Peak- and valleyless Motzkin meanders.

Terms

a(0) =1a(1) =2a(2) =4a(3) =9a(4) =20a(5) =45a(6) =102a(7) =233a(8) =535a(9) =1234a(10) =2857a(11) =6636a(12) =15456a(13) =36085a(14) =84424a(15) =197883a(16) =464585a(17) =1092348a(18) =2571770a(19) =6062109a(20) =14305022a(21) =33789777a(22) =79887365a(23) =189031914a(24) =447639473a(25) =1060798484a(26) =2515512091a(27) =5968826698a(28) =14171068794a(29) =33662866431