a(n) = a(n-1) + a(n-2) - a(n-3) - a(n-8), starting 1,1,2,2,3,3,4,4.

Terms

a(0) =1a(1) =1a(2) =2a(3) =2a(4) =3a(5) =3a(6) =4a(7) =4a(8) =4a(9) =3a(10) =1a(11) =-2a(12) =-7a(13) =-13a(14) =-22a(15) =-32a(16) =-45a(17) =-58a(18) =-72a(19) =-83a(20) =-90a(21) =-88a(22) =-73a(23) =-39a(24) =21a(25) =113a(26) =245a(27) =420a(28) =642a(29) =905