%I #15 Mar 30 2012 18:52:05
%S -1,3,0,3,0,1,3,0,-2,0,3,0,-5,0,-1,3,0,-8,0,1,0,3,0,-11,0,6,0,1,3,0,
%T -14,0,14,0,0,0,3,0,-17,0,25,0,-6,0,-1,3,0,-20,0,39,0,-20,0,-1,0,3,0,
%U -23,0,56,0,-45,0,5,0,1
%N Triangle T(n,k)of the coefficients [x^(n-k)] of the polynomials q(0,x)=-1, q(1,x)=3*x, q(n,x)=x*q(n-1,x)-q(n-2,x) in row n,column k. A companion to A193002(n).
%C a(n)=
%C -1, :-1,
%C 3, 0, :3*x,
%C 3, 0, 1, :3*x^2+1,
%C 3, 0, -2, 0, :3*x^3-2*x,
%C 3, 0, -5, 0, -1,
%C 3, 0, -8, 0, 1, 0
%C 3, 0, -11, 0, 6, 0, 1.
%C Row sum=period 6:repeat -1, 3, 4, 1, -3, 4=-A117378(n)=A117378(n+3).
%F a(n) + A193002(n)=4*A192174(n).
%F a(n) - A193002(n)=2*A053119(n), Chebyshev's S(n,x).
%Y Cf. A192011.
%K sign,tabl
%O 0,2
%A _Paul Curtz_, Aug 20 2011