a(0)=1, a(n) = M(n) + Sum_{k=1..n-1} M(k)*a(n-k-1), where M(n) are the Motzkin numbers (A001006).

A045994

a(0)=1, a(n) = M(n) + Sum_{k=1..n-1} M(k)*a(n-k-1), where M(n) are the Motzkin numbers (A001006).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =7a(4) =18a(5) =47a(6) =125a(7) =337a(8) =918a(9) =2522a(10) =6977a(11) =19415a(12) =54297a(13) =152507a(14) =429974a(15) =1216297a(16) =3450817a(17) =9816460a(18) =27991422a(19) =79989880a(20) =229034820a(21) =656979399a(22) =1887653560a(23) =5431969355a(24) =15653355151a(25) =45167783715a(26) =130491471940a(27) =377426429199

External references