Number of valley-avoiding compositions with positive parts.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =15a(6) =28a(7) =52a(8) =96a(9) =177a(10) =326a(11) =600a(12) =1104a(13) =2032a(14) =3740a(15) =6884a(16) =12672a(17) =23327a(18) =42942a(19) =79052a(20) =145528a(21) =267905a(22) =493192a(23) =907928a(24) =1671424a(25) =3076959a(26) =5664436a(27) =10427772a(28) =19196688a(29) =35339553