34450484domain: NAppears in sequencesExpansion of x*(1-x)/((1-2*x)*(1+3*x)).at n=17A091004a(n) = a(n-1) + 6*a(n-2) for n >= 2, a(0)=1, a(1)=2.at n=16A133467One third of the number of edges in the metrically regular triangulation of the n-th approximation of the Koch snowflake fractal.at n=8A282563