656982433792domain: NAppears in sequencesa(n+2) = 2*a(n+1) + 2*a(n); a(0) = 1, a(1) = 3.at n=27A028859a(n) = 2*a(n-1) + 2*a(n-2) for n > 2, a(0)=1, a(1)=1, a(2)=3.at n=28A155020