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

Terms

a(0) =5a(1) =1a(2) =10a(3) =51a(4) =265a(5) =1376a(6) =7145a(7) =37101a(8) =192650a(9) =1000351a(10) =5194405a(11) =26972376a(12) =140056285a(13) =727253801a(14) =3776325290a(15) =19608880251a(16) =101820726545a(17) =528712512976