3215312955domain: NAppears in sequencesa(n) = Sum_{k=0..n} T(n, k), array T as in A047080.at n=36A047081Expansion of (1-x)/(1+x-x^2+x^3).at n=36A078042Coefficient of x in the reduction of the polynomial (x^2 + x + 1)^n by x^3 -> x^2 + x + 1.at n=13A192807