Number of Motzkin n-paths with two kinds of level steps both of which are final steps.

Terms

a(0) =1a(1) =2a(2) =1a(3) =4a(4) =6a(5) =12a(6) =29a(7) =56a(8) =134a(9) =300a(10) =682a(11) =1624a(12) =3772a(13) =9016a(14) =21597a(15) =51888a(16) =126086a(17) =306636a(18) =750398a(19) =1843864a(20) =4543604a(21) =11242088a(22) =27887730a(23) =69378192a(24) =173050396a(25) =432596216a(26) =1083862132a(27) =2720961520a(28) =6843557944a(29) =17242789104