A123186 - OEIS

%I #6 Dec 26 2022 08:49:49

%S 1,1,1,-2,-2,-2,0,0,0,-8,-8,-8,1112,1112,1112,-16336,-16336,-16336,

%T 29760,29760,29760,108608,108608,108608,112587520,112587520,112587520,

%U -3584451200,-3584451200,-3584451200,17790850560,17790850560,17790850560,208254684160,208254684160

%N This sequence needs a meaningful name.

%t M1 = {{-n, 1, 0}, {0, 1, 0}, {0, 0, 1}};

%t M2 = {{1, 0, 0}, {n, -n, 1}, {0, 0, 1}};

%t M3 = {{1, 0, 0}, {0, 1, 0}, {0, n, -n}};

%t M[n_] := If[Mod[n, 3] == 1, M1, If[Mod[n, 3] == 2, M2, M3]]

%t v[1] = {1, 0, 0}

%t v[n_] := v[n] = M[n].v[n - 1]

%t a1 = Table[v[n][[1]], {n, 1, 50}]

%K uned,sign,easy,less

%O 1,4

%A _Roger L. Bagula_ and _Gary W. Adamson_, Oct 03 2006