Sums of successive Motzkin numbers.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =13a(5) =30a(6) =72a(7) =178a(8) =450a(9) =1158a(10) =3023a(11) =7986a(12) =21309a(13) =57346a(14) =155469a(15) =424206a(16) =1164039a(17) =3210246a(18) =8893161a(19) =24735666a(20) =69051303a(21) =193399578a(22) =543310782a(23) =1530523638a(24) =4322488212a(25) =12236130298a(26) =34713220977a(27) =98677591278