35665403776domain: NAppears in sequencesa(n) = 6*a(n-1) - 2*a(n-2) for n>1; a(1)=1, a(2)=6.at n=14A154244Expansion of x*(1+5*x-2*x^3)/(1-6*x^2+2*x^4).at n=28A249221