a(n) = floor(b(n)), where b(n) = tan(b(n-1)), b(0)=1.

Terms

a(0) =1a(1) =1a(2) =74a(3) =-1a(4) =-2a(5) =-3a(6) =0a(7) =1a(8) =30a(9) =-2a(10) =-2a(11) =29a(12) =1a(13) =4a(14) =-6a(15) =0a(16) =1a(17) =2a(18) =-1a(19) =-1a(20) =-1a(21) =-1a(22) =-2a(23) =-9a(24) =0a(25) =0a(26) =1a(27) =2a(28) =-2a(29) =-35