a(n) = a(n-1) + 36*a(n-2), a(0)=1, a(1)=6.

Terms

a(0) =1a(1) =6a(2) =42a(3) =258a(4) =1770a(5) =11058a(6) =74778a(7) =472866a(8) =3164874a(9) =20188050a(10) =134123514a(11) =860893314a(12) =5689339818a(13) =36681499122a(14) =241497732570