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A204426 Permanent of the n-th principal submatrix of A204425.

%I A204426 #7 Jul 12 2012 00:39:59
%S A204426 1,1,9,34,132,1032,6936,51912,530712,5005152,53529984,707802624,
%T A204426 8714718720,119716185600,1938416832000,29588291712000,496487584512000,
%U A204426 9509523337728000,173318541516288000,3434389946233344000
%N A204426 Permanent of the n-th principal submatrix of A204425.
%t A204426 f[i_, j_] := Mod[2 i + j + 1, 3];
%t A204426 m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
%t A204426 TableForm[m[8]] (* 8x8 principal submatrix *)
%t A204426 Flatten[Table[f[i, n + 1 - i],
%t A204426   {n, 1, 14}, {i, 1, n}]]       (* A204425 *)
%t A204426 Permanent[m_] :=
%t A204426   With[{a = Array[x, Length[m]]},
%t A204426    Coefficient[Times @@ (m.a), Times @@ a]];
%t A204426 Table[Permanent[m[n]], {n, 1, 22}]  (* A204426 *)
%Y A204426 Cf. A204225, A204263.
%K A204426 nonn
%O A204426 1,3
%A A204426 _Clark Kimberling_, Jan 15 2012