a(n) = k*Fibonacci(2*n+1) + (k+1)*Fibonacci(2*n), where k=5.

Terms

a(0) =5a(1) =16a(2) =43a(3) =113a(4) =296a(5) =775a(6) =2029a(7) =5312a(8) =13907a(9) =36409a(10) =95320a(11) =249551a(12) =653333a(13) =1710448a(14) =4478011a(15) =11723585a(16) =30692744a(17) =80354647a(18) =210371197a(19) =550758944a(20) =1441905635a(21) =3774957961a(22) =9882968248a(23) =25873946783a(24) =67738872101a(25) =177342669520a(26) =464289136459