a(n+1) = 2*a(n) + 16*a(n-1), a(0)=0, a(1)=1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =20a(4) =72a(5) =464a(6) =2080a(7) =11584a(8) =56448a(9) =298240a(10) =1499648a(11) =7771136a(12) =39536640a(13) =203411456a(14) =1039409152a(15) =5333401600a(16) =27297349632a(17) =139929124864a(18) =716615843840