a(n) = a(n-1)+a(n-2)+n-4, a(0)=0, a(1)=1.

Terms

a(0) =0a(1) =1a(2) =-1a(3) =-1a(4) =-2a(5) =-2a(6) =-2a(7) =-1a(8) =1a(9) =5a(10) =12a(11) =24a(12) =44a(13) =77a(14) =131a(15) =219a(16) =362a(17) =594a(18) =970a(19) =1579a(20) =2565a(21) =4161a(22) =6744a(23) =10924a(24) =17688a(25) =28633a(26) =46343a(27) =74999a(28) =121366a(29) =196390