a(n) = 3*a(n-1) + 4*a(n-2) - a(n-3) + 3*a(n-4) + 4*a(n-5).

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =4a(5) =16a(6) =63a(7) =252a(8) =1008a(9) =4033a(10) =16132a(11) =64528a(12) =258111a(13) =1032444a(14) =4129776a(15) =16519105a(16) =66076420a(17) =264305680a(18) =1057222719a(19) =4228890876a(20) =16915563504a(21) =67662254017a(22) =270649016068