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

Terms

a(0) =1a(1) =2a(2) =11a(3) =57a(4) =296a(5) =1537a(6) =7981a(7) =41442a(8) =215191a(9) =1117397a(10) =5802176a(11) =30128277a(12) =156443561a(13) =812346082a(14) =4218173971a(15) =21903215937a(16) =113734253656a(17) =590574484217