Table T(n,k) = -2*T(n-1,k)+T(n-1,k+1) = T(n,k-4), 0<=n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =-1a(4) =0a(5) =1a(6) =-3a(7) =2a(8) =1a(9) =-5a(10) =8a(11) =-4a(12) =-7a(13) =18a(14) =-20a(15) =9a(16) =32a(17) =-56a(18) =49a(19) =-25a(20) =-120a(21) =161a(22) =-123a(23) =82a(24) =401a(25) =-445a(26) =328a(27) =-284a(28) =-1247a(29) =1218