a(n) = 4*a(n-1) + 17*a(n-2), a(1)=1, a(2)=4.

Terms

a(0) =1a(1) =4a(2) =33a(3) =200a(4) =1361a(5) =8844a(6) =58513a(7) =384400a(8) =2532321a(9) =16664084a(10) =109705793a(11) =722112600a(12) =4753448881a(13) =31289709724a(14) =205967469873