Generalized Motzkin paths with no hills and 4-horizontal steps (even coefficients).

A099171

Generalized Motzkin paths with no hills and 4-horizontal steps (even coefficients).

Terms

    a(0) =0a(1) =2a(2) =3a(3) =12a(4) =37a(5) =132a(6) =473a(7) =1753a(8) =6612a(9) =25355a(10) =98492a(11) =386812a(12) =1533269a(13) =6126254a(14) =24647539a(15) =99766315a(16) =405994556a(17) =1660072482a(18) =6816932349a(19) =28101049860a(20) =116243913509a(21) =482387204447

External references