137428992domain: NAppears in sequencesExpansion of x^4*(1 - x)^2*(1 - 3*x^2 - 2*x^3 + x^4 - x^5)/(1 - 2*x)^3.at n=27A192886a(n) = 2^n*F(n)*F(n+1), where F = A000045.at n=12A292277