A118677 Number of Motzkin paths of length n in 3D with no level steps at odd level.

1, 2, 6, 18, 60, 202, 718, 2600, 9748, 37270, 146058, 582548, 2367028, 9761890, 40844168, 173001018, 741193056, 3207480526, 14008373662, 61683982696, 273658651700, 1222314257450, 5493414465900, 24828463984518

Offset: 0

Author

Max Alekseyev, May 19 2006

Keywords

• nonn

Crossrefs

Cf. A090344.

Formula

EXPCONV of A090344 with itself, i.e. a(n) = sum_{k=0}^n binomial(n,k)*A090344(k)*A090344(n-k)