%I #18 Dec 26 2022 09:46:48
%S 0,1,1,1,1,1,5,1,-5,-7,1,-1,33,1,-1,-255,1,255,1,1,-2049,16385,1,
%T -32769,262145,1,-524289,1,1,-8388609,-268435455,1,268435455,
%U 8589934593,1,-1,-549755813887,1,-1,70368744177665,1,-70368744177665,1,1,9007199254740991,-1152921504606846975
%N This sequence needs a meaningful name.
%t a = 1;
%t M1 = {{2, 0, 1}, {a - 1, a, 0}, {a - 3, 1, a - 1}};
%t v[0] = {0, 1, 1}; v[1] = {1, 1, 1};
%t v[n_] := v[n] = MatrixPower[M1, n].v[n - 1];
%t b = Flatten[Table[v[n], {n, 0, 15}]]
%Y Cf. A103191.
%K sign,uned
%O 0,7
%A _Roger L. Bagula_, Mar 18 2005