a(n) = F(n+4) * F(n+1) - 4 * (-1)^n where F(n) = A000045(n) are the Fibonacci numbers.

Terms

a(0) =9a(1) =12a(2) =43a(3) =101a(4) =276a(5) =711a(6) =1873a(7) =4892a(8) =12819a(9) =33549a(10) =87844a(11) =229967a(12) =602073a(13) =1576236a(14) =4126651a(15) =10803701a(16) =28284468a(17) =74049687a(18) =193864609a(19) =507544124a(20) =1328767779a(21) =3478759197a(22) =9107509828a(23) =23843770271a(24) =62423801001a(25) =163427632716a(26) =427859097163