Number of 4-colored Motzkin paths of length n with no peaks at level 1.

A202020

Number of 4-colored Motzkin paths of length n with no peaks at level 1.

Terms

    a(0) =1a(1) =4a(2) =16a(3) =68a(4) =305a(5) =1428a(6) =6914a(7) =34368a(8) =174438a(9) =900392a(10) =4712034a(11) =24944268a(12) =133335497a(13) =718664500a(14) =3901458106a(15) =21313500576a(16) =117081025390a(17) =646328535800

External references