Triangle read by rows giving coefficients of the trigonometric expansion of Cos(n*x).

Terms

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