a(n) = 5*a(n-1) - a(n-2) with a(0)=1, a(1)=7.

Terms

a(0) =1a(1) =7a(2) =34a(3) =163a(4) =781a(5) =3742a(6) =17929a(7) =85903a(8) =411586a(9) =1972027a(10) =9448549a(11) =45270718a(12) =216905041a(13) =1039254487a(14) =4979367394a(15) =23857582483a(16) =114308545021a(17) =547685142622