a(n) = 4*a(n-1) + 4*a(n-2) for n > 1; a(0) = 1, a(1) = 8.

Terms

a(0) =1a(1) =8a(2) =36a(3) =176a(4) =848a(5) =4096a(6) =19776a(7) =95488a(8) =461056a(9) =2226176a(10) =10748928a(11) =51900416a(12) =250597376a(13) =1209991168a(14) =5842354176a(15) =28209381376a(16) =136206942208a(17) =657665294336