a(n) = a(n-1) + a(n-3) + a(n-4), n >= 4, with initial terms 1,1,-2,-1.

Terms

a(0) =1a(1) =1a(2) =-2a(3) =-1a(4) =1a(5) =0a(6) =-3a(7) =-3a(8) =-2a(9) =-5a(10) =-11a(11) =-16a(12) =-23a(13) =-39a(14) =-66a(15) =-105a(16) =-167a(17) =-272a(18) =-443a(19) =-715a(20) =-1154a(21) =-1869a(22) =-3027a(23) =-4896a(24) =-7919a(25) =-12815a(26) =-20738a(27) =-33553a(28) =-54287a(29) =-87840