a(n) = p(n) - p(n-1) - p(n-2) + p(n-5), where p(n) = A000041(n).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =-1a(8) =-1a(9) =-2a(10) =-3a(11) =-5a(12) =-6a(13) =-10a(14) =-13a(15) =-18a(16) =-24a(17) =-33a(18) =-42a(19) =-57a(20) =-72a(21) =-94a(22) =-120a(23) =-154a(24) =-192a(25) =-245a(26) =-305a(27) =-382a(28) =-473a(29) =-588