a(0) = 1, a(1) = 8, a(n) = 56*a(n-2) - a(n-1).

Terms

a(0) =1a(1) =8a(2) =48a(3) =400a(4) =2288a(5) =20112a(6) =108016a(7) =1018256a(8) =5030640a(9) =51991696a(10) =229724144a(11) =2681810832a(12) =10182741232a(13) =139998665360a(14) =430234843632