%I #3 Mar 30 2012 17:26:53
%S 1,2,6,18,60,202,718,2600,9748,37270,146058,582548,2367028,9761890,
%T 40844168,173001018,741193056,3207480526,14008373662,61683982696,
%U 273658651700,1222314257450,5493414465900,24828463984518
%N Number of Motzkin paths of length n in 3D with no level steps at odd level.
%F EXPCONV of A090344 with itself, i.e. a(n) = sum_{k=0}^n binomial(n,k)*A090344(k)*A090344(n-k)
%Y Cf. A090344.
%K nonn
%O 0,2
%A _Max Alekseyev_, May 19 2006