8599552domain: NAppears in sequencesa(n) = 2^n * C(n+1), where C(n) = A000108(n) Catalan numbers.at n=9A003645Riordan array (c(2x)^2,xc(2x)), c(x) the g.f. of A000108.at n=45A167432Triangle read by rows, T(n,k) for 0<=k<=n, generalizes the Motzkin lattice paths with weights of A003645.at n=45A201639