Extended Motzkin numbers, Sum_{k>=0} C(n,k)*C(k), where C(k) is the extended Catalan number A057977(k).

A189912

Extended Motzkin numbers, Sum_{k>=0} C(n,k)*C(k), where C(k) is the extended Catalan number A057977(k).

Terms

    a(0) =1a(1) =2a(2) =4a(3) =10a(4) =25a(5) =66a(6) =177a(7) =484a(8) =1339a(9) =3742a(10) =10538a(11) =29866a(12) =85087a(13) =243478a(14) =699324a(15) =2015082a(16) =5822619a(17) =16865718a(18) =48958404a(19) =142390542a(20) =414837699a(21) =1210439958a(22) =3536809521a(23) =10347314544a(24) =30306977757a(25) =88861597426a(26) =260798283502a(27) =766092871654

External references