Total area under all the level steps in all peakless Motzkin paths of length n (n>=0).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =12a(6) =36a(7) =104a(8) =292a(9) =810a(10) =2224a(11) =6058a(12) =16408a(13) =44240a(14) =118848a(15) =318339a(16) =850608a(17) =2268206a(18) =6037892a(19) =16048945a(20) =42604344a(21) =112974302a(22) =299284044a(23) =792164740a(24) =2095161996a(25) =5537651796a(26) =14627504340a(27) =38616930931a(28) =101899265656