a(n) = sin((2*n+5)*Pi/6)*(n+1)*2^(n+1).

Terms

a(0) =1a(1) =-4a(2) =-24a(3) =-32a(4) =80a(5) =384a(6) =448a(7) =-1024a(8) =-4608a(9) =-5120a(10) =11264a(11) =49152a(12) =53248a(13) =-114688a(14) =-491520a(15) =-524288a(16) =1114112a(17) =4718592a(18) =4980736a(19) =-10485760a(20) =-44040192a(21) =-46137344a(22) =96468992a(23) =402653184a(24) =419430400a(25) =-872415232a(26) =-3623878656a(27) =-3758096384