69792188337domain: NAppears in sequencesa(n) = (F(2*n-1) + F(n+1))/2 where F(n) is a Fibonacci number.at n=28A005207Constant term of the reduction of the polynomial p(n,x)=(1/2)((x+1)^n+(x-1)^n) by x^2->x+1.at n=28A192352