104660992domain: NAppears in sequencesa(n) = 2*a(n-1) + 4*a(n-2), a(0)=1, a(1)=2.at n=16A063727Horadam sequence (0,1,4,2).at n=17A085449a(n) = Sum_{k=0..n} binomial(2n+1, 2k)*5^(n-k).at n=8A102592a(1) = 1, a(n) = 2*a(n-1) if n is even; a(n) = a(n-1)*Fibonacci((n+1)/2)/Fibonacci((n-1)/2) if n is odd.at n=32A171648