See Mathematica program.

Terms

a(0) =-3a(1) =1a(2) =1a(3) =1a(4) =-4a(5) =1a(6) =0a(7) =-8a(8) =6a(9) =-1a(10) =-1a(11) =-12a(12) =19a(13) =-8a(14) =1a(15) =-2a(16) =-15a(17) =44a(18) =-34a(19) =10a(20) =-1a(21) =-3a(22) =-16a(23) =84a(24) =-104a(25) =53a(26) =-12a(27) =1a(28) =6a(29) =-59