Number of Motzkin paths of length n up to reversal.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =13a(6) =32a(7) =70a(8) =179a(9) =435a(10) =1142a(11) =2947a(12) =7889a(13) =21051a(14) =57192a(15) =155661a(16) =427795a(17) =1179451a(18) =3271214a(19) =9102665a(20) =25434661a(21) =71282431a(22) =200406472a(23) =564905068a(24) =1596435581a(25) =4521772933a(26) =12835116530a(27) =36504093693a(28) =104012240063a(29) =296871993373