a(n) = 4*a(n-1) + 10*a(n-2), with a(1)=0 and a(2)=1.

Terms

a(0) =0a(1) =1a(2) =4a(3) =26a(4) =144a(5) =836a(6) =4784a(7) =27496a(8) =157824a(9) =906256a(10) =5203264a(11) =29875616a(12) =171535104a(13) =984896576a(14) =5654937344a(15) =32468715136a(16) =186424233984