a(n) = Fibonacci(4*n + 1).

Terms

a(0) =1a(1) =5a(2) =34a(3) =233a(4) =1597a(5) =10946a(6) =75025a(7) =514229a(8) =3524578a(9) =24157817a(10) =165580141a(11) =1134903170a(12) =7778742049a(13) =53316291173a(14) =365435296162