506037domain: NAppears in sequencesa(n) = Fibonacci(2*n+1) - 2^(n-1).at n=13A061667Diagonal sums of triangle A008949.at n=26A079284For even n, a(n) = a(n-2) + a(n-1) + 2^(n/2-2), n>2. For odd n, a(n) = a(n-2) + a(n-1).at n=27A079289